Yesterday and today I had problems downloading new apps from the Windows App Store on my Windows 8 tablet. I finally found a post in the Windows Forums about resetting the App Store Cache. Basically, run this utility from the command line or Start | Run menu.
AMD have finally released a beta Catalyst driver and control center app that works with Windows 8. This solves the problem I’ve had for the last month of video not scaled to the whole size of my external monitor when running full resolution.