diff --git a/VocBase/simple-collection.c b/VocBase/simple-collection.c
index b8772a027a..cb0df87385 100644
--- a/VocBase/simple-collection.c
+++ b/VocBase/simple-collection.c
@@ -327,6 +327,10 @@ static TRI_doc_mptr_t CreateDocument (TRI_sim_collection_t* collection,
   // update indexes
   // .............................................................................
 
+  // -----------------------------------------------------------------------------
+  // update indexes
+  // -----------------------------------------------------------------------------
+
   // generate create header
   if (res == TRI_ERROR_NO_ERROR) {
 
@@ -546,6 +550,10 @@ static TRI_doc_mptr_t const UpdateDocument (TRI_sim_collection_t* collection,
   // update indexes
   // .............................................................................
 
+  // -----------------------------------------------------------------------------
+  // update indexes
+  // -----------------------------------------------------------------------------
+
   // update the header
   if (res == TRI_ERROR_NO_ERROR) {
     TRI_doc_mptr_t update;
@@ -935,6 +943,8 @@ static TRI_doc_mptr_t const CreateShapedJson (TRI_doc_collection_t* document,
   TRI_df_marker_t* result;
   TRI_sim_collection_t* collection;
 
+  TRI_set_errno(TRI_ERROR_NO_ERROR);
+
   collection = (TRI_sim_collection_t*) document;
 
   if (type == TRI_DOC_MARKER_DOCUMENT) {
@@ -1027,6 +1037,8 @@ static TRI_doc_mptr_t const UpdateShapedJson (TRI_doc_collection_t* document,
   TRI_doc_mptr_t const* header;
   TRI_sim_collection_t* collection;
 
+  TRI_set_errno(TRI_ERROR_NO_ERROR);
+
   collection = (TRI_sim_collection_t*) document;
 
   // get an existing header pointer
@@ -2167,6 +2179,10 @@ static int UpdateImmediateIndexes (TRI_sim_collection_t* collection,
     return TRI_ERROR_AVOCADO_UNIQUE_CONSTRAINT_VIOLATED;
   }
 
+  if (constraint) {
+    return TRI_VOC_ERROR_UNIQUE_VIOLATED;
+  }
+
   return result;
 }
 
@@ -2861,7 +2877,7 @@ static TRI_index_t* CreateSkiplistIndexSimCollection (TRI_sim_collection_t* coll
   
   if (idx != NULL) {
     TRI_DestroyVector(&paths);
-    TRI_DestroyVectorPointer(&fields);
+    TRI_DestroyVectorString(&names);
 
     LOG_TRACE("skiplist-index already created");
     return idx;
diff --git a/VocBase/vocbase.c b/VocBase/vocbase.c
index eaa7a242c8..5df70055e9 100644
--- a/VocBase/vocbase.c
+++ b/VocBase/vocbase.c
@@ -788,6 +788,7 @@ TRI_vocbase_t* TRI_OpenVocBase (char const* path) {
   }
 
   // .............................................................................
+
   // setup vocbase structure
   // .............................................................................