Anyone having shuttering with 58xx video cards should check the clocks in your profile, C:\Users\xxxxxxxx\AppData\Local\ATI. After the recommended uninstall method of an ATI card and working installation of a 58xx. Catalyst can revert back to the old card clocks. Correct by deleting the profile along with the profile folder. Seems the problem can repeat when saving custom profiles. Good Luck Bretware
