Issues with the ATi Tray Tool and my Radeon X800XTPE

[evolucion8]

Is quite strange, I have tested all the Ati Tray Tools versions and usually locks up the display when I play games or use 3DMark, no matter if it is overclocked or not, I think that may be it has something to do with the way that the ATT interacts with System settings like AGP Writes etc, What can that be? Disabling AGP Writes may stop this annoying thing? I have a beefy 500W Antec Power Supply, PAT enabled, and a 128MB AGP Aperture. ANd I have used memtest and Prime95 to test and find any hardware failure and none I have found. WHen I use CCC I find no problems, but it is a resource hog and I really like ATT. What can that be? Any suggestions will be appreciated and sorry for my bad english, still improving though.