couple things could cause this. If rpl vid card doesn't work, you can look into the PSU. Even though 550, maybe its a defective regulator?? Could be the voltage to the AGP like was mentioned above. Also, to anyone else that has this problem, after installing the drivers, go into safe mode and see if it works for awhile in there (IMPORTANT!!!). If it works in there, then u may want to check you screen refresh rate. Also, disable APM in the bios and see if that solves it. APM can cause problems at times.
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