oh its a GT not XT. Herm, well I am not sure about 64 bit support but why not just use the driver alone and try something other than CCC to manage like ati tray tools and just the AMD released display driver. I don't know 64 bit windows is so pointless to use because there is little advantage as still, even with vista, nothing uses the 64 bit capabilities. It makes sense to just upgrade but as long as the largest body of people are still using 32 bit 64 bit is a waste of time as it is horribly supported and won't be adopted until the greater number uses 64 bit rather than 32. Thats my only idea for you even though thinking about it I'm sure its a driver issue. However, CCC is very picky about what it likes and sometimes can be buggy as I was using tray tools for the fan rev on my x1900xt because the stock fan speeds are screwed up and 70C is too hot for me for a card so I rather have it a little louder and colder than extremely hot but CCC was causing weird issues with tray tools and for some odd reason it caused my 3d mark score to be 1100 points low and when I just used the display driver and tray tools to do my configuring then it was perfect! CCC blows, period