Now I know, never, ever, ever rename a roll in finder after it's been created.
If that's what you've done then rebuilding with iPhoto Library Manager won't help because it won;t find the pics you've moved/changed either.
In your case you need to start over.
To create and populate a new library:
Note this will give you a working library with the same Rolls and pictures as before, however, you will lose your albums, keywords, modified versions, books, calendars etc.
Move the iPhoto Library to the desktop
Launch iPhoto. It will ask if you wish to create a new Library. Say Yes.
Go into the iPhoto Library on your desktop and find the Originals folder. From the Originals folder drag the individual Roll Folders to the iPhoto Window and it will recreate them in the new library.
When you're sure all is well you can delete the iPhoto Library on your desktop.
In the future, in addition to your usual back up routine, you might like to make a copy of the library6.iPhoto file whenever you have made changes to the library as protection against database corruption.
Regards
TD