It was an standalone WP installation. But, in fact once I´m working deeply with the plug-in, can see that there is images used that appeared like: Attached (0) Embebed (0) ready to Delete and what happens is that if you delete them may be are in use and I must reload them again.
The rename issue is very useful, but I can´t trust the erasing duplicates issue since I´ve erased some that appeared unused.
