I'm also on windows 8.1, as is a friend of mine and we also have this bug.

I've tried legacy hooks on and off, auto, setting manually to x86 and x64 for both clients each, making sure everything is enabled etc. And it hasn't helped. If there's any way to help find out what's wrong I'd be happy to.

For a 'workaround' atm of sorts I run with the streaming overlay, right click on it to disable everything I don't want and set it to always on top and transparent