GTX 260 temperature/ comp freezing

I just put a new PC together and have been experiencing random freezes where I am unable to open the task manager and am forced to manually restart the computer.  I opened the side of the case, put a huge fan blowing in and ran speedfan and noticed that  my computer stops freezing even when I left it alone overnight.  However, when I run a game like Far Cry 2 or Crysis it always freezes very quickly.  The temperature of my graphics card (gtx260) gets to about 60C on speedfan. I am running:
Intel Duo E8500

4 GB (2X2gb) corsair Ram

EVGA GTX260

Gigabyte GA-EP45-DS3L LGA 775 Intel P45 ATX mobo

It seems like this is a heat problem but I didnt realize that my computer would completely freeze even with two pc fans and a giant fan blowing directly into my case.  If anyone thinks this is actually a different problem I am overlooking, could you let me know? Also, what would you suggest as a good (preferably inexpensive) cooling alternative to purchase? Thanks!

doubtful that its cooling/ overheating problem, at least not with those temps, you don't overclock do you?

but it might just be some instability problems, check the bios and see what the voltage is for your ram, a lot of the time a board will undervolt the ram and it will cause system instability and random crashes, check what the normal voltage is for your ram and try manually setting it to that if it isn't already set to that, then download prime95 and run it for 5-6hrs, or just overnight and see if you get any red lights, it should tell you if your system is unstable