diff --git a/src/MGRAST/lib/resources2/matrix.pm b/src/MGRAST/lib/resources2/matrix.pm
index c6d94867..8a815dcf 100644
--- a/src/MGRAST/lib/resources2/matrix.pm
+++ b/src/MGRAST/lib/resources2/matrix.pm
@@ -226,14 +226,9 @@ sub instance {
         $self->return_data( {"ERROR" => "no valid ids submitted and/or found: ".join(", ", @ids)}, 401 );
     }
 
-    # get cached if exists
-    my $cached = $self->memd->get($self->url_id);
-    if ($cached) {
-        # do a runaround on ->return_data
-        print $self->header;
-        print $cached;
-        exit 0;
-    }
+    # return cached if exists
+    $self->return_cached();
+    
     # prepare data
     my $data = $self->prepare_data([keys %$mgids], $type);
     $self->return_data($data, undef, 1); # cache this!
@@ -257,7 +252,7 @@ sub prepare_data {
     my $leaf_node = 0;
     my $matrix_id = join("_", sort @$data).'_'.join("_", ($type, $glvl, $source, $rtype, $eval, $ident, $alen));
     if (@filter > 0) {
-        $matrix_id .= join("_", sort map { $_ =~ s/\s+/_/ } @filter)."_".$fsrc;
+        $matrix_id .= join("_", sort map { $_ =~ s/\s+/_/g } @filter)."_".$fsrc;
     }
 
     # initialize analysis obj with mgids
diff --git a/src/MGRAST/lib/resources2/metagenome.pm b/src/MGRAST/lib/resources2/metagenome.pm
index aa92c560..9734aa88 100644
--- a/src/MGRAST/lib/resources2/metagenome.pm
+++ b/src/MGRAST/lib/resources2/metagenome.pm
@@ -123,14 +123,9 @@ sub instance {
         $self->return_data( {"ERROR" => "insufficient permissions to view this data"}, 401 );
     }
 
-    # get cached if exists
-    my $cached = $self->memd->get($self->url_id);
-    if ($cached) {
-        # do a runaround on ->return_data
-        print $self->header;
-        print $cached;
-        exit 0;
-    }
+    # return cached if exists
+    $self->return_cached();
+    
     # prepare data
     my $data = $self->prepare_data( [$job] );
     $data = $data->[0];
diff --git a/src/MGRAST/lib/resources2/project.pm b/src/MGRAST/lib/resources2/project.pm
index edf57871..90366587 100644
--- a/src/MGRAST/lib/resources2/project.pm
+++ b/src/MGRAST/lib/resources2/project.pm
@@ -117,14 +117,9 @@ sub instance {
         $self->return_data( {"ERROR" => "insufficient permissions to view this data"}, 401 );
     }
 
-    # get cached if exists
-    my $cached = $self->memd->get($self->url_id);
-    if ($cached) {
-        # do a runaround on ->return_data
-        print $self->header;
-        print $cached;
-        exit 0;
-    }
+    # return cached if exists
+    $self->return_cached();
+    
     # prepare data
     my $data = $self->prepare_data( [$project] );
     $data = $data->[0];
diff --git a/src/MGRAST/lib/resources2/resource.pm b/src/MGRAST/lib/resources2/resource.pm
index a3ac79a5..d7cc0571 100644
--- a/src/MGRAST/lib/resources2/resource.pm
+++ b/src/MGRAST/lib/resources2/resource.pm
@@ -235,6 +235,19 @@ sub check_pagination {
     }
 }
 
+# return cached data if exists
+sub return_cached {
+    my ($self) = @_;
+    
+    my $cached = $self->memd->get($self->url_id);
+    if ($cached) {
+        # do a runaround on ->return_data
+        print $self->header;
+        print $cached;
+        exit 0;
+    }
+}
+
 # print the actual data output
 sub return_data {
     my ($self, $data, $error, $cache_me) = @_;
@@ -468,6 +481,14 @@ sub get_shock_query {
     }
 }
 
+# I can't find a perl library that gives me random UUID !
+sub uuidv4 {
+    my ($self) = @_;
+    my $uuid = `python -c "import uuid; print uuid.uuid4()"`;
+    chomp $uuid;
+    return $uuid;
+}
+
 sub toFloat {
     my ($self, $x) = @_;
     return $x * 1.0;