So for some reason my 1gbx2 stopped working correctly, i test each stick individually, stick 1 would work in all slots but 3, stick two would work in all slots but 3. I previously had both sticks in dual channel=slot 1 and 3, I was curious to know if it was the mobo or the ram, so I ran the sticks indivisually in 1 and 4, 1 and 2, and ram posted, everything booted up( the numbers are dimm slots.) My 2x1gb G skill would not run in dual channel, but my old 2x512 off brand would run and post with prime95, very confused at this point. I thought maybe it was the 3rd slot and I would have to rma the mobo. I basically switched up every combination at this point, running my 2x512 and my 2x1gb ram in all slots with combinations of both. I'm currently running 3 Gbs ddr2 5-5-5-15 atm, with both type of ram. Has anyone heard of something happening like this. Pc is running fine now with 1x2gb and 512x1 gb in dual channel. This is scaring me. Hope someone can help with issue or maybe its a ram issue, When I recently booted up windows xp told me some data might not exist anymore. pfft, wtf, any suggestions>?