Pausing causes problems with opening menus

This isn’t exactly my problem, it’s more of my friend’s problem, but this is a big problem for him.
Whenever he pauses and unpauses, the only things he can do are move around and use the mouse. He can’t pause again or open any menus. When this happened to me, I simply deleted the cache folder and the file “cl.db” and everything worked fine after that, but it does nothing for him. I have searched Google for answers, but I have only found one thread about it, and it had no answers. Please help?