hello i have a slight problem with my sapphire X800 GTO^2, i´ve always had a problem when passing 540mhz memory frequency, no problem, i thought i had 2.0ns like some of the GTO^2 on the market, when pushing beyond that value and and run the artifact tester on ATItools, the machine would reboot after a couple of minutes of testing, the issue rose when a couple of days ago, i replaced the stock cooler with a zalman VF700-AlCu, on noise issues, when i pull off the stock cooler, 1.6ns memory chips, whats going on here ? heat problems ? voltage problems ? any suggestions ? another issue i´ve noticed, the memory chips on the back are only cooled by a patetic strip of aluminium which is actually used to keep that cooler in place, the VF700 came with individual aluminium memory heat sinks, i have´nt had the time to test how far the memory would go on those heatsinks, i wonder if those chips on the back of the card would be the problem.