diff --git a/.hgtags b/.hgtags
index 34dd1729707..9362ac875a6 100644
--- a/.hgtags
+++ b/.hgtags
@@ -18,4 +18,4 @@ a4113cc1cb5eaa68091c9a73375f00555b66dd11 release_2013.01.13
 81fbe25bd02edcd53065e8e4476dd1dfb5a72cf2 latest_2013.11.04
 2a756ca2cb1826db7796018e77d12e2dd7b67603 latest_2014.02.10
 ca45b78adb4152fc6e7395514d46eba6b7d0b838 release_2014.08.11
-7e22f35798522100ff03e1fdd4eced962b292360 latest_2014.08.11
+109b170188e97fbfc2c998ec174aff9546dd1bd8 latest_2014.08.11
diff --git a/lib/galaxy/dataset_collections/structure.py b/lib/galaxy/dataset_collections/structure.py
index e067caaec23..917ec1698ff 100644
--- a/lib/galaxy/dataset_collections/structure.py
+++ b/lib/galaxy/dataset_collections/structure.py
@@ -35,9 +35,9 @@ class Tree( object ):
         return self._walk_collections( dict_map( lambda hdca: hdca.collection, hdca_dict ) )
 
     def _walk_collections( self, collection_dict ):
-        for ( identifier, substructure ) in self.children:
+        for index, ( identifier, substructure ) in enumerate( self.children ):
             def element( collection ):
-                return collection[ identifier ]
+                return collection[ index ]
 
             if substructure.is_leaf:
                 yield dict_map( element, collection_dict )
diff --git a/lib/galaxy/web/base/controller.py b/lib/galaxy/web/base/controller.py
index 8b704700f21..5216e3e350a 100644
--- a/lib/galaxy/web/base/controller.py
+++ b/lib/galaxy/web/base/controller.py
@@ -27,7 +27,7 @@ from galaxy.web import error, url_for
 from galaxy.web.form_builder import AddressField, CheckboxField, SelectField, TextArea, TextField
 from galaxy.web.form_builder import build_select_field, HistoryField, PasswordField, WorkflowField, WorkflowMappingField
 from galaxy.workflow.modules import module_factory, WorkflowModuleInjector, MissingToolException
-from galaxy.model.orm import eagerload, eagerload_all, desc
+from galaxy.model.orm import eagerload, eagerload_all, desc, not_
 from galaxy.security.validate_user_input import validate_publicname
 from galaxy.util.sanitize_html import sanitize_html
 from galaxy.model.item_attrs import Dictifiable, UsesAnnotations
@@ -2683,7 +2683,7 @@ class SharableMixin:
         item = self.get_item( trans, id )
         if item:
             # Only update slug if slug is not already in use.
-            if trans.sa_session.query( item.__class__ ).filter_by( user=item.user, slug=new_slug, importable=True ).count() == 0:
+            if trans.sa_session.query( item.__class__ ).filter_by( user=item.user, slug=new_slug ).count() == 0:
                 item.slug = new_slug
                 trans.sa_session.flush()
 
@@ -2718,7 +2718,9 @@ class SharableMixin:
         # add integer to end.
         new_slug = slug_base
         count = 1
-        while sa_session.query( item.__class__ ).filter_by( user=item.user, slug=new_slug, importable=True ).count() != 0:
+        # Ensure unique across model class and user and don't include this item
+        # in the check in case it has previously been assigned a valid slug.
+        while sa_session.query( item.__class__ ).filter( item.__class__.user == item.user, item.__class__.slug == new_slug, item.__class__.id != item.id).count() != 0:
             # Slug taken; choose a new slug based on count. This approach can
             # handle numerous items with the same name gracefully.
             new_slug = '%s-%i' % ( slug_base, count )