I got coruption on grid too with x1950pro sometimes it works sometimes it doesnt.
edit = post 5 pic i got and happened with a few diff drivers. cant be sure but i think when i play a ut3 game then grid i got the corruption tho i cant be sure.
I've got that card and its working fine with the 8.5 drivers. I did get graphics corruption with earlier drivers though using the Atitray tools program and Geometry Instancing was not selected.
What sort of corruption is it? I also had overheating aberations which seem to be fixed after Alternate Dvi Operation mode was deactivated, as it was turned on for some reason.