Corwin75 who develops for the PS has released a very useful tool called PARAM Edit.A  This handy dandy tool lets you modify your PS3 Saves.A  See below for an official quote from Corwin75.

"Hello.
It's complicated you change your ps3 saves by lack of knowledge or you have simply no hex editor? The solution is very simple. PARAM Edit is a small program that I just create to modify your saves in several areas:
- Modify the protection of saves (lock / unlock copies)
- Make compatibility saves with your account
- Modify the saves details
- Change the title of the saves
- Edit sub-title of the saves

Sources are being modified to be especially easy to read and understand each operation.

EXPLANATION:
For compatibility. You need a save to make it compatible with a game and a save from your account with the same game."

Source:A  http://www.ps3hax.net/showthread.php?t=35435