diff --git a/IPython/html/static/base/js/utils.js b/IPython/html/static/base/js/utils.js
index ad038722ebf..aa4dcbe0d0f 100644
--- a/IPython/html/static/base/js/utils.js
+++ b/IPython/html/static/base/js/utils.js
@@ -419,6 +419,19 @@ IPython.utils = (function (IPython) {
         }
         return url;
     };
+    
+    
+    var encode_uri_components = function (uri) {
+        // encode just the components of a multi-segment uri,
+        // leaving '/' separators
+        return uri.split('/').map(encodeURIComponent).join('/');
+    }
+    
+    var url_join_encode = function () {
+        // join a sequence of url components with '/',
+        // encoding each component with encodeURIComponent
+        return encode_uri_components(url_path_join.apply(null, arguments));
+    };
 
 
     var splitext = function (filename) {
@@ -458,6 +471,8 @@ IPython.utils = (function (IPython) {
         autoLinkUrls : autoLinkUrls,
         points_to_pixels : points_to_pixels,
         url_path_join : url_path_join,
+        url_join_encode : url_join_encode,
+        encode_uri_components : encode_uri_components,
         splitext : splitext,
         always_new : always_new,
         browser : browser
diff --git a/IPython/html/static/notebook/js/menubar.js b/IPython/html/static/notebook/js/menubar.js
index 85419f5099c..7de234506fc 100644
--- a/IPython/html/static/notebook/js/menubar.js
+++ b/IPython/html/static/notebook/js/menubar.js
@@ -77,7 +77,7 @@ var IPython = (function (IPython) {
             IPython.notebook.new_notebook();
         });
         this.element.find('#open_notebook').click(function () {
-            window.open(utils.url_path_join(
+            window.open(utils.url_join_encode(
                 that.baseProjectUrl(),
                 'tree',
                 that.notebookPath()
@@ -93,7 +93,7 @@ var IPython = (function (IPython) {
                 IPython.notebook.save_notebook({async : false});
             }
             
-            var url = utils.url_path_join(
+            var url = utils.url_join_encode(
                 that.baseProjectUrl(),
                 'files',
                 that.notebookPath(),
diff --git a/IPython/html/static/notebook/js/notebook.js b/IPython/html/static/notebook/js/notebook.js
index 5f53e1bd5f2..e396b120723 100644
--- a/IPython/html/static/notebook/js/notebook.js
+++ b/IPython/html/static/notebook/js/notebook.js
@@ -79,15 +79,11 @@ var IPython = (function (IPython) {
     };
 
     Notebook.prototype.notebookName = function() {
-        var name = $('body').data('notebookName');
-        name = decodeURIComponent(name);
-        return name;  
+        return $('body').data('notebookName');
     };
     
     Notebook.prototype.notebookPath = function() {
-        var path = $('body').data('notebookPath');
-        path = decodeURIComponent(path);
-        return path
+        return $('body').data('notebookPath');
     };
     
     /**
@@ -1689,10 +1685,10 @@ var IPython = (function (IPython) {
             }
         }
         $([IPython.events]).trigger('notebook_saving.Notebook');
-        var url = utils.url_path_join(
-            this.baseProjectUrl(),
+        var url = utils.url_join_encode(
+            this._baseProjectUrl,
             'api/notebooks',
-            this.notebookPath(),
+            this.notebook_path,
             this.notebook_name
         );
         $.ajax(url, settings);
@@ -1743,15 +1739,15 @@ var IPython = (function (IPython) {
      * @method save_notebook_error
      * @param {jqXHR} xhr jQuery Ajax object
      * @param {String} status Description of response status
-     * @param {String} error_msg HTTP error message
+     * @param {String} error HTTP error message
      */
-    Notebook.prototype.save_notebook_error = function (xhr, status, error_msg) {
-        $([IPython.events]).trigger('notebook_save_failed.Notebook');
+    Notebook.prototype.save_notebook_error = function (xhr, status, error) {
+        $([IPython.events]).trigger('notebook_save_failed.Notebook', [xhr, status, error]);
     };
 
     Notebook.prototype.new_notebook = function(){
-        var path = this.notebookPath();
-        var base_project_url = this.baseProjectUrl();
+        var path = this.notebook_path;
+        var base_project_url = this._baseProjectUrl;
         var settings = {
             processData : false,
             cache : false,
@@ -1761,7 +1757,7 @@ var IPython = (function (IPython) {
             success : function (data, status, xhr){
                 var notebook_name = data.name;
                 window.open(
-                    utils.url_path_join(
+                    utils.url_join_encode(
                         base_project_url,
                         'notebooks',
                         path,
@@ -1771,7 +1767,7 @@ var IPython = (function (IPython) {
                 );
             }
         };
-        var url = utils.url_path_join(
+        var url = utils.url_join_encode(
             base_project_url,
             'api/notebooks',
             path
@@ -1781,8 +1777,8 @@ var IPython = (function (IPython) {
 
 
     Notebook.prototype.copy_notebook = function(){
-        var path = this.notebookPath();
-        var base_project_url = this.baseProjectUrl();
+        var path = this.notebook_path;
+        var base_project_url = this._baseProjectUrl;
         var settings = {
             processData : false,
             cache : false,
@@ -1791,7 +1787,7 @@ var IPython = (function (IPython) {
             data : JSON.stringify({copy_from : this.notebook_name}),
             async : false,
             success : function (data, status, xhr) {
-                window.open(utils.url_path_join(
+                window.open(utils.url_join_encode(
                     base_project_url,
                     'notebooks',
                     data.path,
@@ -1799,7 +1795,7 @@ var IPython = (function (IPython) {
                 ), '_blank');
             }
         };
-        var url = utils.url_path_join(
+        var url = utils.url_join_encode(
             base_project_url,
             'api/notebooks',
             path
@@ -1821,10 +1817,10 @@ var IPython = (function (IPython) {
             error : $.proxy(that.rename_error, this)
         };
         $([IPython.events]).trigger('rename_notebook.Notebook', data);
-        var url = utils.url_path_join(
-            this.baseProjectUrl(),
+        var url = utils.url_join_encode(
+            this._baseProjectUrl,
             'api/notebooks',
-            this.notebookPath(),
+            this.notebook_path,
             this.notebook_name
         );
         $.ajax(url, settings);
@@ -1832,19 +1828,20 @@ var IPython = (function (IPython) {
     
     
     Notebook.prototype.rename_success = function (json, status, xhr) {
-        this.notebook_name = json.name
-        var name = this.notebook_name
-        var path = json.path
+        this.notebook_name = json.name;
+        var name = this.notebook_name;
+        var path = json.path;
         this.session.rename_notebook(name, path);
         $([IPython.events]).trigger('notebook_renamed.Notebook', json);
     }
 
-    Notebook.prototype.rename_error = function (json, status, xhr) {
+    Notebook.prototype.rename_error = function (xhr, status, error) {
         var that = this;
         var dialog = $('<div/>').append(
             $("<p/>").addClass("rename-message")
             .html('This notebook name already exists.')
         )
+        $([IPython.events]).trigger('notebook_rename_failed.Notebook', [xhr, status, error]);
         IPython.dialog.modal({
             title: "Notebook Rename Error!",
             body: dialog,
@@ -1889,10 +1886,10 @@ var IPython = (function (IPython) {
             error : $.proxy(this.load_notebook_error,this),
         };
         $([IPython.events]).trigger('notebook_loading.Notebook');
-        var url = utils.url_path_join(
+        var url = utils.url_join_encode(
             this._baseProjectUrl,
             'api/notebooks',
-            this.notebookPath(),
+            this.notebook_path,
             this.notebook_name
         );
         $.ajax(url, settings);
@@ -1974,12 +1971,13 @@ var IPython = (function (IPython) {
      * 
      * @method load_notebook_error
      * @param {jqXHR} xhr jQuery Ajax object
-     * @param {String} textStatus Description of response status
-     * @param {String} errorThrow HTTP error message
+     * @param {String} status Description of response status
+     * @param {String} error HTTP error message
      */
-    Notebook.prototype.load_notebook_error = function (xhr, textStatus, errorThrow) {
+    Notebook.prototype.load_notebook_error = function (xhr, status, error) {
+        $([IPython.events]).trigger('notebook_load_failed.Notebook', [xhr, status, error]);
         if (xhr.status === 400) {
-            var msg = errorThrow;
+            var msg = error;
         } else if (xhr.status === 500) {
             var msg = "An unknown error occurred while loading this notebook. " +
             "This version can load notebook formats " +
@@ -2034,10 +2032,10 @@ var IPython = (function (IPython) {
      * @method list_checkpoints
      */
     Notebook.prototype.list_checkpoints = function () {
-        var url = utils.url_path_join(
-            this.baseProjectUrl(),
+        var url = utils.url_join_encode(
+            this._baseProjectUrl,
             'api/notebooks',
-            this.notebookPath(),
+            this.notebook_path,
             this.notebook_name,
             'checkpoints'
         );
@@ -2085,8 +2083,8 @@ var IPython = (function (IPython) {
      * @method create_checkpoint
      */
     Notebook.prototype.create_checkpoint = function () {
-        var url = utils.url_path_join(
-            this.baseProjectUrl(),
+        var url = utils.url_join_encode(
+            this._baseProjectUrl,
             'api/notebooks',
             this.notebookPath(),
             this.notebook_name,
@@ -2172,8 +2170,8 @@ var IPython = (function (IPython) {
      */
     Notebook.prototype.restore_checkpoint = function (checkpoint) {
         $([IPython.events]).trigger('notebook_restoring.Notebook', checkpoint);
-        var url = utils.url_path_join(
-            this.baseProjectUrl(),
+        var url = utils.url_join_encode(
+            this._baseProjectUrl,
             'api/notebooks',
             this.notebookPath(),
             this.notebook_name,
@@ -2220,8 +2218,8 @@ var IPython = (function (IPython) {
      */
     Notebook.prototype.delete_checkpoint = function (checkpoint) {
         $([IPython.events]).trigger('notebook_restoring.Notebook', checkpoint);
-        var url = utils.url_path_join(
-            this.baseProjectUrl(),
+        var url = utils.url_join_encode(
+            this._baseProjectUrl,
             'api/notebooks',
             this.notebookPath(),
             this.notebook_name,
diff --git a/IPython/html/static/notebook/js/savewidget.js b/IPython/html/static/notebook/js/savewidget.js
index 56e62f3eae9..8a0183ca79e 100644
--- a/IPython/html/static/notebook/js/savewidget.js
+++ b/IPython/html/static/notebook/js/savewidget.js
@@ -128,8 +128,8 @@ var IPython = (function (IPython) {
     SaveWidget.prototype.update_address_bar = function(){
         var nbname = IPython.notebook.notebook_name;
         var path = IPython.notebook.notebookPath();
-        var state = {path : utils.url_path_join(path,nbname)};
-        window.history.replaceState(state, "", utils.url_path_join(
+        var state = {path : utils.url_join_encode(path, nbname)};
+        window.history.replaceState(state, "", utils.url_join_encode(
             "/notebooks",
             path,
             nbname)
diff --git a/IPython/html/static/services/kernels/js/kernel.js b/IPython/html/static/services/kernels/js/kernel.js
index 9aa91aa2ce8..c1badfbdad0 100644
--- a/IPython/html/static/services/kernels/js/kernel.js
+++ b/IPython/html/static/services/kernels/js/kernel.js
@@ -113,7 +113,7 @@ var IPython = (function (IPython) {
         $([IPython.events]).trigger('status_restarting.Kernel', {kernel: this});
         if (this.running) {
             this.stop_channels();
-            var url = utils.url_path_join(this.kernel_url, "restart");
+            var url = utils.url_join_encode(this.kernel_url, "restart");
             $.post(url,
                 $.proxy(this._kernel_started, this),
                 'json'
@@ -133,7 +133,7 @@ var IPython = (function (IPython) {
             ws_url = prot + location.host + ws_url;
         }
         this.ws_url = ws_url;
-        this.kernel_url = utils.url_path_join(this.base_url, this.kernel_id);
+        this.kernel_url = utils.url_join_encode(this.base_url, this.kernel_id);
         this.start_channels();
     };
 
diff --git a/IPython/html/static/services/sessions/js/session.js b/IPython/html/static/services/sessions/js/session.js
index a2bf694696b..0f0c4a99733 100644
--- a/IPython/html/static/services/sessions/js/session.js
+++ b/IPython/html/static/services/sessions/js/session.js
@@ -44,7 +44,7 @@ var IPython = (function (IPython) {
                 }
             },
         };
-        var url = utils.url_path_join(this._baseProjectUrl, 'api/sessions');
+        var url = utils.url_join_encode(this._baseProjectUrl, 'api/sessions');
         $.ajax(url, settings);
     };
     
@@ -64,7 +64,7 @@ var IPython = (function (IPython) {
             data: JSON.stringify(model),
             dataType : "json",
         };
-        var url = utils.url_path_join(this._baseProjectUrl, 'api/sessions', this.id);
+        var url = utils.url_join_encode(this._baseProjectUrl, 'api/sessions', this.id);
         $.ajax(url, settings);
     };
     
@@ -76,7 +76,7 @@ var IPython = (function (IPython) {
             dataType : "json",
         };
         this.kernel.running = false;
-        var url = utils.url_path_join(this._baseProjectUrl, 'api/sessions', this.id);
+        var url = utils.url_join_encode(this._baseProjectUrl, 'api/sessions', this.id);
         $.ajax(url, settings);
     };
     
diff --git a/IPython/html/static/tree/js/clusterlist.js b/IPython/html/static/tree/js/clusterlist.js
index 8be3b30af1f..4108c125422 100644
--- a/IPython/html/static/tree/js/clusterlist.js
+++ b/IPython/html/static/tree/js/clusterlist.js
@@ -51,7 +51,7 @@ var IPython = (function (IPython) {
             dataType : "json",
             success : $.proxy(this.load_list_success, this)
         };
-        var url = utils.url_path_join(this.baseProjectUrl(), 'clusters');
+        var url = utils.url_join_encode(this.baseProjectUrl(), 'clusters');
         $.ajax(url, settings);
     };
 
@@ -137,7 +137,7 @@ var IPython = (function (IPython) {
                     }
                 };
                 status_col.html('starting');
-                var url = utils.url_path_join(
+                var url = utils.url_join_encode(
                     that.baseProjectUrl(),
                     'clusters',
                     that.data.profile,
@@ -179,7 +179,7 @@ var IPython = (function (IPython) {
                 }
             };
             status_col.html('stopping');
-            var url = utils.url_path_join(
+            var url = utils.url_join_encode(
                 that.baseProjectUrl(),
                 'clusters',
                 that.data.profile,
diff --git a/IPython/html/static/tree/js/notebooklist.js b/IPython/html/static/tree/js/notebooklist.js
index 5367c65c3a7..2ee7a190057 100644
--- a/IPython/html/static/tree/js/notebooklist.js
+++ b/IPython/html/static/tree/js/notebooklist.js
@@ -147,7 +147,7 @@ var IPython = (function (IPython) {
                              },this)
         };
 
-        var url = utils.url_path_join(
+        var url = utils.url_join_encode(
                 this.baseProjectUrl(),
                 'api',
                 'notebooks',
@@ -177,7 +177,7 @@ var IPython = (function (IPython) {
             var nbname = utils.splitext(name)[0];
             var item = this.new_notebook_item(i);
             this.add_link(path, nbname, item);
-            name = utils.url_path_join(this.notebookPath(), name);
+            name = utils.url_path_join(path, name);
             if(this.sessions[name] === undefined){
                 this.add_delete_button(item);
             } else {
@@ -214,10 +214,10 @@ var IPython = (function (IPython) {
         item.find(".item_name").text(nbname);
         item.find("a.item_link")
             .attr('href',
-                utils.url_path_join(
+                utils.url_join_encode(
                     this.baseProjectUrl(),
                     "notebooks",
-                    this.notebookPath(),
+                    path,
                     nbname + ".ipynb"
                 )
             ).attr('target','_blank');
@@ -254,7 +254,7 @@ var IPython = (function (IPython) {
                         that.load_sessions();
                     }
                 };
-                var url = utils.url_path_join(
+                var url = utils.url_join_encode(
                     that.baseProjectUrl(),
                     'api/sessions',
                     session
@@ -294,11 +294,11 @@ var IPython = (function (IPython) {
                                         parent_item.remove();
                                     }
                                 };
-                                var url = utils.url_path_join(
+                                var url = utils.url_join_encode(
                                     notebooklist.baseProjectUrl(),
                                     'api/notebooks',
                                     notebooklist.notebookPath(),
-                                     nbname + '.ipynb'
+                                    nbname + '.ipynb'
                                 );
                                 $.ajax(url, settings);
                             }
@@ -339,7 +339,7 @@ var IPython = (function (IPython) {
                     }
                 };
 
-                var url = utils.url_path_join(
+                var url = utils.url_join_encode(
                     that.baseProjectUrl(),
                     'api/notebooks',
                     that.notebookPath(),
@@ -373,7 +373,7 @@ var IPython = (function (IPython) {
             success : function (data, status, xhr) {
                 var notebook_name = data.name;
                 window.open(
-                    utils.url_path_join(
+                    utils.url_join_encode(
                         base_project_url,
                         'notebooks',
                         path,
@@ -382,7 +382,7 @@ var IPython = (function (IPython) {
                 );
             }
         };
-        var url = utils.url_path_join(
+        var url = utils.url_join_encode(
             base_project_url,
             'api/notebooks',
             path
diff --git a/IPython/html/tests/casperjs/test_cases/save_notebook.js b/IPython/html/tests/casperjs/test_cases/save_notebook.js
new file mode 100644
index 00000000000..affe05454e6
--- /dev/null
+++ b/IPython/html/tests/casperjs/test_cases/save_notebook.js
@@ -0,0 +1,105 @@
+//
+// Test saving a notebook with escaped characters
+//
+
+casper.notebook_test(function () {
+    // don't use unicode with ambiguous composed/decomposed normalization
+    // because the filesystem may use a different normalization than literals.
+    // This causes no actual problems, but will break string comparison.
+    var nbname = "has#hash and space and unicø∂e.ipynb";
+    
+    this.evaluate(function (nbname) {
+        IPython.notebook.notebook_name = nbname;
+        IPython._save_success = IPython._save_failed = false;
+        $([IPython.events]).on('notebook_saved.Notebook', function () {
+            IPython._save_success = true;
+        });
+        $([IPython.events]).on('notebook_save_failed.Notebook',
+            function (event, xhr, status, error) {
+                IPython._save_failed = "save failed with " + xhr.status + xhr.responseText;
+        });
+        IPython.notebook.save_notebook();
+    }, {nbname:nbname});
+    
+    this.waitFor(function () {
+        return this.evaluate(function(){
+            return IPython._save_failed || IPython._save_success;
+        });
+    });
+    
+    this.then(function(){
+        var success_failure = this.evaluate(function(){
+            return [IPython._save_success, IPython._save_failed];
+        });
+        this.test.assertEquals(success_failure[1], false, "Save did not fail");
+        this.test.assertEquals(success_failure[0], true, "Save OK");
+        
+        var current_name = this.evaluate(function(){
+            return IPython.notebook.notebook_name;
+        });
+        this.test.assertEquals(current_name, nbname, "Save with complicated name");
+    });
+    
+    this.thenEvaluate(function(){
+        $([IPython.events]).on('checkpoint_created.Notebook', function (evt, data) {
+            IPython._checkpoint_created = true;
+        });
+        IPython._checkpoint_created = false;
+        IPython.notebook.save_checkpoint();
+    });
+    
+    this.waitFor(function () {
+        return this.evaluate(function(){
+            return IPython._checkpoint_created;
+        });
+    });
+    
+    this.then(function(){
+        var checkpoints = this.evaluate(function(){
+            return IPython.notebook.checkpoints;
+        });
+        this.test.assertEquals(checkpoints.length, 1, "checkpoints OK");
+    });
+
+    this.then(function(){
+        var baseUrl = this.get_notebook_server();
+        this.open(baseUrl);
+    });
+
+    this.waitForSelector('.list_item');
+    
+    this.then(function(){
+        var notebook_url = this.evaluate(function(nbname){
+            var escaped_name = encodeURIComponent(nbname);
+            var return_this_thing;
+            $("a.item_link").map(function (i,a) {
+                if (a.href.indexOf(escaped_name) >= 0) {
+                    return_this_thing = a.href;
+                    return;
+                }
+            });
+            return return_this_thing;
+        }, {nbname:nbname});
+        this.test.assertEquals(notebook_url == null, false, "Escaped URL in notebook list");
+        // open the notebook
+        this.open(notebook_url);
+    });
+    
+    // wait for the notebook
+    this.waitForSelector("#notebook");
+    
+    this.waitFor(function(){
+        return this.evaluate(function(){
+            return IPython.notebook || false;
+        });
+    });
+    
+    this.then(function(){
+        // check that the notebook name is correct
+        var notebook_name = this.evaluate(function(){
+            return IPython.notebook.notebook_name;
+        });
+        this.test.assertEquals(notebook_name, nbname, "Notebook name is correct");
+    });
+    
+});