If you go here:
http://www.journeysystems.com/?power_supply_calculator
You can check your system and see if your PSU is powerful enough. The other way is to unplug some non critical units (like CD ROMs, case fans ect) and see if your rig runs better..

__________________
AMD X2 BLACK EDITION 3.2GHz SAMURAI COOLER::GA-M51 MB-HEATPIPE CHIPSET COOLER::3GB XMS2 PC6400 RAM::GEFORCE 8800 GTS 320MB 575/900MHz::160GB BARRACUDA RAID 0::SOUNDBLASTER AUDIGY::LITE-ON DVD RAMDRIVE/PIONEER DVD::HIPER MODULAR 530W PSU::THERMALTAKE ARMOUR Jr CASE::RAZER COPPERHEAD MOUSE::VISTA HOME PREMIUM SP1