You can try that.. Or maybe it's the game file you are trying to play also. Does the PSP give you an error code or something after the game boot loads?
See if you can format your mem stick.. If it still doesn't work i'm really not sure what's wrong with it since i never encountered any problems after updating to 5.50GEN-D2 on my slim.. If it was me i'd probably just reflash the 5.50 update..
Well keep us posted with the progress, we'll work it out.. :taz:
Bookmarks