(PS3) Grand Theft Auto IV save data - is it region locked?

Tweet

Ok, I used to have a GTA IV - Region 2 game and already finished it. I still have my save data on my PS3. Then I bought a GTA IV - Greatest Hits - Region 1 a few days ago because I wanted to play GTA IV again using my old data. When I popped in the CD of this R1 GTA IV, the system says "Error loading save file - starting a new game." It seems to me that this GTA IV - Greatest Hits - Region 1 cannot load my old save data from my R2 GTA IV. Anybody got this experience? Another question is, if ever I'm going to play this R1 version of the game, will it create another trophy set separated from my R2 trophy set? I don't want to get all those hard trophies again and I just want to get all those I missed with my old save data.