3870 problem - goes power save mode

[bastic]

Hey All.
Recently I bought new bits and pieces for my rig and among them is 3870.
The problem is that after 1-2hours of play my monitor goes into power save mode while all the game sounds are still in background. so i suppose its GPU connected problem...card is not O/C...fans are on auto in rivatuner...
any suggestions ?
Thx

 

[LoadsaMoney]

Could be overheating, have you checked the temps to see what its on when it goes off.

 

[bastic]

never seen it going above 68degrees but in few seconds time i switch between game and lets say Everest it can go down ....
edit :
just checked it in NFSrostreet and temp didnt went higher than 61degrees.....