diff --git a/src/event.js b/src/event.js
index ac0da6b7e8..1d92362799 100644
--- a/src/event.js
+++ b/src/event.js
@@ -304,7 +304,7 @@ jQuery.event = {
 		}
 		event.namespace = namespaces.join(".");
 		event.namespace_re = new RegExp("(^|\\.)" + namespaces.join("\\.(?:.*\\.)?") + "(\\.|$)");
-		
+
 		// Handle a global trigger
 		if ( !elem ) {
 			// Don't bubble custom events when global (to avoid too much overhead)
@@ -574,6 +574,9 @@ jQuery.Event = function( src ) {
 			}
 		}
 
+		// Always ensure a type has been explicitly set
+		this.type = src.type;
+
 		// Events bubbling up the document may have been marked as prevented
 		// by a handler lower down the tree; reflect the correct value.
 		this.isDefaultPrevented = (src.defaultPrevented || src.returnValue === false ||
@@ -1030,10 +1033,18 @@ jQuery.each(["live", "die"], function( i, name ) {
 			return this;
 		}
 
+		if ( name === "die" && !types &&
+					origSelector && origSelector[0] === "." ) {
+
+			context.unbind( origSelector );
+
+			return this;
+		}
+
 		if ( data === false || jQuery.isFunction( data ) ) {
 			fn = data || returnFalse;
 			data = undefined;
-		}	
+		}
 
 		types = (types || "").split(" ");
 
diff --git a/src/traversing.js b/src/traversing.js
index fb5946bba8..e0f40151da 100644
--- a/src/traversing.js
+++ b/src/traversing.js
@@ -73,9 +73,9 @@ jQuery.fn.extend({
 	},
 
 	is: function( selector ) {
-		return !!selector && (typeof selector === "string" ?
+		return !!selector && ( typeof selector === "string" ?
 			jQuery.filter( selector, this ).length > 0 :
-			this.filter( selector ).length > 0);
+			this.filter( selector ).length > 0 );
 	},
 
 	closest: function( selectors, context ) {
@@ -298,13 +298,18 @@ jQuery.extend({
 
 // Implement the identical functionality for filter and not
 function winnow( elements, qualifier, keep ) {
+
+	// Can't pass null or undefined to indexOf in Firefox 4
+	// Set to 0 to skip string check
+	qualifier = qualifier || 0;
+
 	if ( jQuery.isFunction( qualifier ) ) {
 		return jQuery.grep(elements, function( elem, i ) {
 			var retVal = !!qualifier.call( elem, i, elem );
 			return retVal === keep;
 		});
 
-	} else if ( qualifier && qualifier.nodeType ) {
+	} else if ( qualifier.nodeType ) {
 		return jQuery.grep(elements, function( elem, i ) {
 			return (elem === qualifier) === keep;
 		});
diff --git a/test/unit/event.js b/test/unit/event.js
index cefdf58337..b1fd919f58 100644
--- a/test/unit/event.js
+++ b/test/unit/event.js
@@ -2022,6 +2022,27 @@ test("delegate with submit", function() {
 	jQuery(document).undelegate();
 });
 
+test("undelegate() with only namespaces", function(){
+	expect(2);
+
+	var $delegate = jQuery("#liveHandlerOrder"),
+			count = 0;
+
+	$delegate.delegate("a", "click.ns", function(e) {
+		count++;
+	});
+
+	jQuery("a", $delegate).eq(0).trigger("click.ns");
+
+	equals( count, 1, "delegated click.ns");
+
+	$delegate.undelegate(".ns");
+
+	jQuery("a", $delegate).eq(1).trigger("click.ns");
+
+	equals( count, 1, "no more .ns after undelegate");
+});
+
 test("Non DOM element events", function() {
 	expect(1);
 
diff --git a/test/unit/traversing.js b/test/unit/traversing.js
index 6228a0b98f..140b337aa8 100644
--- a/test/unit/traversing.js
+++ b/test/unit/traversing.js
@@ -72,7 +72,7 @@ test("is(String|undefined)", function() {
 });
 
 test("is(jQuery)", function() {
-	expect(24);
+	expect(23);
 	ok( jQuery('#form').is( jQuery('form') ), 'Check for element: A form is a form' );
 	ok( !jQuery('#form').is( jQuery('div') ), 'Check for element: A form is not a div' );
 	ok( jQuery('#mark').is( jQuery('.blog') ), 'Check for class: Expected class "blog"' );
@@ -83,7 +83,6 @@ test("is(jQuery)", function() {
 	ok( !jQuery('#en').is( jQuery('[lang="de"]') ), 'Check for attribute: Expected attribute lang to be "en", not "de"' );
 	ok( jQuery('#text1').is( jQuery('[type="text"]') ), 'Check for attribute: Expected attribute type to be "text"' );
 	ok( !jQuery('#text1').is( jQuery('[type="radio"]') ), 'Check for attribute: Expected attribute type to be "text", not "radio"' );
-	ok( jQuery('#text2').is( jQuery(':disabled') ), 'Check for pseudoclass: Expected to be disabled' );
 	ok( !jQuery('#text1').is( jQuery(':disabled') ), 'Check for pseudoclass: Expected not disabled' );
 	ok( jQuery('#radio2').is( jQuery(':checked') ), 'Check for pseudoclass: Expected to be checked' );
 	ok( !jQuery('#radio1').is( jQuery(':checked') ), 'Check for pseudoclass: Expected not checked' );
@@ -223,10 +222,6 @@ test("closest(Array)", function() {
 	same( jQuery("body").closest(["span","html"]), [{selector:"html", elem:document.documentElement, level:2}], "closest([body, html])" );
 });
 
-<<<<<<< HEAD
-test("not(Selector|undefined)", function() {
-	expect(11);
-=======
 test("closest(jQuery)", function() {
 	expect(8);
 	var $child = jQuery("#nothiddendivchild"),
@@ -243,9 +238,8 @@ test("closest(jQuery)", function() {
 	ok( $child.closest( $body.add($parent) ).is('#nothiddendiv'), "Closest ancestor retrieved." );
 });
 
-test("not(Selector)", function() {
-	expect(7);
->>>>>>> 1a167767305202797cf4c839eb64bd7adfb00182
+test("not(Selector|undefined)", function() {
+	expect(11);
 	equals( jQuery("#main > p#ap > a").not("#google").length, 2, "not('selector')" );
 	same( jQuery("p").not(".result").get(), q("firstp", "ap", "sndp", "en", "sap", "first"), "not('.class')" );
 	same( jQuery("p").not("#ap, #sndp, .result").get(), q("firstp", "en", "sap", "first"), "not('selector, selector')" );