I wonder is this the same thing that you are experiencing from time to time in test.
I have deleted as you suggested and they recreated themselves to no avail.
The issue of locking and then testing is something I have done frequently as changes are being made but still the menu items are not re-appearing.
I also exported the bsv, created a new business space and then imported it but still it is happening. Is there something more fundamentally wrong with the business space definition ?