I sugest using the factory reset option on Adrenaline and restart and see how that is. Did you have a particular OC setting on your 6800?
Select reset and select CPU (unless you have an overclock setting as well for cpu+gpu) If so, reset everything and restart.
If that doesn't help, uninstall the drivers from control panel/ use amd uninstall tool and reboot.
Wait for Windows to install native drivers, reboot and install the latest from the AMD website.