http://www2.ati.com/drivers/wxp-w2k-...22a-014266.exe
Upon making changes to certain monitor calibration software, the gamma settings will not be applied or loaded for the display. Color and gamma profiles for third party applications and games are also affected.

Users who are experiencing this issue are advised to download and install this driver HotFix.

A future CATALYST release is expected to address this issue. Further information will appear on this page as it becomes available.

http://www.ati.com/support/infobase/4501.html