This is getting a little frustrating. I thght ATI fixed the lockup/GreySOD probms with Cat 10.2. I guess not. Here is an ATI certified game S.T.A.L.K.E.R. Call of Pripyat with an ATI 5870 and see the results. It plays fine on my Nvidia systems. I am on my 2nd 5870 with the same issues, and I have a 3rd still in its box for Xfire. Sent a support to Sapphire and will see what they reply with. Also a support submit to ATI. This happens occasionally with Youtube HD vids also. Corruption then lockup and sometimes BSOD follows.