solved. Just wanted to post in case anyone else ever has this issue. From the wacom tech support - updating windows corrupts the wacom drivers and causes the glitch, so you have to uninstall and then reinstall the drivers.
i had same problem. Uninstalled driver. But then :-). My original driver for intuos2 GD-0608-U didn't want to install on w 8.1.
So i searched, installed -> didn't work, other search, other driver - installed, didn't work. That went on 5 times.
Finaly i found drivers for my oldie at http://www.tablet4u.nl/item/108-30/in... , they have more drivers. Anyway for my GD-0608-U it worked. Hurray.
for anyone searching and coming to this page. And thanks Nick for the hint.