Hi all, I have a 15 inch Unibody MacBook Pro, Late 2008, so it obviously came with Leopard. All was well and amazing until I upgraded to Snow Leopard. At first, it all seemed perfect, everything ran fine for a while. Then one day my computer froze, and by freezing I mean completely, so the mouse wouldn't move and not even the Caps Lock key's light would turn green when I pressed it. The only way out was to force the computer off by holding the power button for a few seconds. This freezing then happened approximately once or twice per week and has been like this for a few months now. Very often the computer would just freeze while playing music on iTunes, and the last few sounds of the song would repeat endlessly. Often it would freeze while just displaying the screen saver for a while. So it doesn't seem to be happening due to overheating or some specific user action or application. Also, sometimes the computer will just go black and reboot on its own, and at other times the screen would flicker every few seconds while in a frozen state. But most often it just freezes and requires me to reboot it by holding down the power button. The only important thing I have noticed is that the problem only happens when I use the Nvidia 9600M graphics card instead of the 9400 (This is done by going to System Preferences > Energy Saver > Graphics and choosing "Higher Performance", instead of "Better Battery Life"). When I use the lower performance 9400 card, everything runs fine. However, I definitely need the speed that the higher performance card can produce, so this is a big problem. I didn't use the higher performance card much while I had Leopard, though I did use it from time to time, so it might be that the problem was there but I just didn't notice it. However, I really have the impression that it's related to Snow Leopard. I have posted this problem to some other forums, but the only answer I got was "Try reinstalling Snow Leopard" and "Your graphics card is probably faulty". I will try to do a clean reinstall of Snow Leopard as a last resort, but since it's a big hassle, I would like some other advice at the moment. Also, my Mac is no longer under warranty so if it's a hardware issue, I am not going to have the money to get it fixed, so I'll just have to get used to my computer crashing every few days. Oh and before you ask: I have OS X 10.6.2, I have repaired permissions many times, including doing it by booting from the Snow Leopard install disk, I ran the Apple hardware test (it can be run from the Application Install Disk by pressing D during boot) and I did a Repair Disk. I don't think I have any app that would cause a conflict with the system, I mostly use these: Skype, Safari, Mail, Final Cut Pro, and Photoshop. I also reset the SMC today, so it will take a few days before I know whether that helped or not, but until then, let's suppose that it didn't help. Thanks!