I've gotten a couple blue screens in the past, seemingly randomly, but this one is the only one I can reproduce and is stopping me from playing a game. I installed "Mafia" and ran it fine the first couple times I played it. Now, whenever I go into the game, and start playing it, about 5 seconds later, I get a Blue Screen, with the message "IRQL_NOT_LESS_OR_EQUAL" and it does a memory dump. Is there any way to tell what is causing this error, or how to fix it? I installed SP1 on XP, but it was no help.