I have a pretty new athlon xp 1.8ghz based system that originally had a 256MB PNY 333mhz DDR dimm in the first slot. Yesterday I added a 512MB kingston 333mhz DDR dimm in the second slot. Before long the screen would flicker and then take on a purpleish tint. If I turn it off the problem goes away, but soon comes back. When I remove the new dimm the problem seems to go away, and when I remove the original card but leave the new one there also appears to be no problem. Could there be a compatibility problem? heat? Thanks for your help.