This IS a hardware/system question, but it happens with some games. This is the problem: When playing Mafia it "skips" badly now and then, but I know it's not a graphics issue. I asked one of my friends and he suggested defraging. After I defraged, it ran smoothly, then when I re-opened it a hour later the same thing happened again. Another thing I noticed that after I defraged, about three hours later it said I needed to defrag AGAIN!! [basically, I have the alarm to go off when the HD goes pass 5% fragmentation, so, first it was at 2% then three hours later it was at 8%]! WHAT CAN THE PROBLEM BE, IM STRESSING HERE!!!?? Thanx in advance! Also, Mafia is the only game that acts like that. My GTA 3 runs PERFECTLY!!!!