Chrono Cross Savegame Problem

So I played CC on my old 2GB stick until after I cured the girl with the medicine. So now I got a 4GB stick and transferred all Savegames exactly to PSP/SAVEDATA and the CC save under SCUS94640, just like on my older stick. But now CC does not recognize this savegame. I also tried to start a new game, save and replace the data, but didn't work either. Why does my old Savegame not work? The savegame is properly shown in the XMB, but like I said the game itself says "no Savegame"

PSP Fat
5.00M33-3
SanDisk MS Pro Duo 4GB (Sony 2GB Brown old stick)

Are you using the same popsloader?