Fallout 3 patch for version BLUS-30455 was released on November 19, 2009 for the PS3. It fixes issues with loading save games from original version of Fallout 3 in this Canadian release of the Game of the Year Edition.
If you only have saves from the Fallout 3 (BLUS-30185) on your PS3, when you load Fallout 3: Game of the Year Edition (BLUS-30455), your saves will not initially appear in your saved games list.
In order to get them to appear, you'll need to start a new game on the GOTY disc and make a new save. You can do this as soon as you can start moving around during the “Baby Steps” quest. Once you've made a a GOTY save, all of your original BLUS-30185 saves will appear in your saved games list.
If you have already made any save with the GOTY disc, then the old saves should appear immediately after updating, barring any issues with hitting the total displayed saved game limit (130). If you have more than 130 saves between the two releases, you'll need to delete older saves for the newest ones to appear.
Any BLUS-30185 saves made may take a while to load. If your saves are taking a long time to load you might want to resave them and back up or remove the old ones.
To clarify, if the user has a large number of saves that exceeds this limit, the saves will still be on their system, they just won't be able to see them in game. The limitation just affects how many saves are listed in the in-game menus. If they have saves they cannot get to, they'll need to delete some that are in the list.