This seems a little buggy to me:
1) browse a collection and select an item to view
2) from the item's summary page, click on the "edit" button
3) click "cancel" on the "Edit Item" page
4) instead of being returned to the item's summary page, you'll see the
"Edit or Delete Item" page that requests a handle/ID, and that has the
admin menu sidebar.
Are there other places in DSpace where the user might have arrived that the
same page from two different routes? Any thoughts on fixes?