Rename highly buggy

I'm having problems with renaming a diagram (or "physical data model"). My new tables randomly get renamed to one specific old diagram. These new tables are copies of the old diagram (or copies of copies, which might go under a different name). Have tried renaming in the folder view or in the model details view for specific diagram, logging in/out, various combinations of logging in/out with opening/not opening the diagrams and different browsers.