Try download new driver from Nvidia site that may fix the problems - I used 2xXFX Nvidia Geforce 9600GT XXX and enabled SLI (used 174.74 driver that latest one) plus used Thermaltake Toughpower 1000w PSU - that worked prefect that keep cooler and very fast run - no problems at all -- I also plugged 4-pins Molex into PCIE_12v to give more power that what it said on motherboard manual (used GA-M59SLI-S5 + Athlon 64 X2 6400+ 3.2Ghz + 4Gb RAM DDR2-800)