I've played GTA LCS from a UMD the day i recived my PSP, and it worked smooth. I can't remember if it was the original 2.81 firmware or 3.40OE-A. After i sent back the UMD as you know, 3.40 OE-A could play the game but it needed a UMD, any UMD, which i lacked because of my CORE version. Now then the M33 CFW(woohoo) i could run the game but it runs quite jerky even with 333Mhz on the CPU
. Do you have any clue?