I have an Asus M2N Plus Sli Vista Edition mobo. I had 3 gigs of ram installed all dual channel ddr2 pc 6400. It was 2x1G Patriots and 2x512MB crucial ballistix. I tried installing two more 1G patriots and i get the blue screen after POST message. If i swap one of the 1G for a 512MB it works out fine. I know none of the RAM is faulty ive tried moving it all around. Ive tried messing around with a few timings in the BIOS but i have no idea what im doing. Any help would be great. Thanks