raedon 9800 pro artifacting

today i noticed artifacting while gaming. it's the first time this has happened on this box, and it doesn't happen while not gaming. my video card is unmodified and at stock speeds. the first thing that comes to mind is overheating. admittedly, i do need to get my ac serviced. however, my case temp is only one degree higher than normal (37C instead of 36C) and has been at that temp for a few days now. could anything other than overheating be causing this? also, i should be getting an arctic silencer soon, but in the meantime can i just reseat my stock heatsink with arctic silver to solve the problem?

Yes, I'd clean all the dust off, and reseat the HS..

dan

i cleaned the dust but that didn't help much. where can i find a tut on reseating the heatsink? those little clips look confusing.