Funny - I'm not seeing any issue with WindowBlinds 8,0 and Avast 8.0.1489 (the latest version) on my Windows 8 laptop. It might be a driver issue with alexgerry's system or missing updates. I've used several different themes (mostly the newest essorant themes...) and aren't experiencing the problems that have been reported. The only issue I have noted is that when I run the Stardock-made Win8 Metro theme there's a tendency for it to "stick" to the top of the screen if a window gets too close to the top - not having any other major problems with newer skins.
BTW - I reinstalled the Sabertooth skin from WindowBlinds 7.41 and it works fine on the system - not sure why it was removed from the preinstalled skins but I'm submitting my vote to put it back in.