It's not overheating. 60 degrees isn't hot. I would suggest that there are other issues with that video card and/or drivers. Run DXDiag and do a full analysis of Dx protocols. Otherwise, I wuld seriously be looking at buying another card or RMA the 7800gt.
Noli Nothis Permittere Te Terere!!
EVGA 680i, Dual EVGA 8800GT'S (650/950), 4 gigs OCZ DDR2 1066, Intel Q9450 at 3.8 Ghz, Koolance Water Cooled, Dual Plextor16x DL DVD+/-RW. Dual WD 250gb 16mb Cache Sata 3.0. 3DMark06 score = 19,168.