I just tried to play Wintermute for the first time, and was unable to progress past Mackenzie pulling the shrapnel out of his hand because it wasn't registering my clicking at all. I thought maybe it was just too laggy so I turned everything to low, but that didn't change anything. I was able to play before the Wintermute update, so if I can't anymore, I'm not gonna be a happy camper, I have to admit.
64 bit Win7, dual core Intel processor, 6g RAM.
EDIT: I tried out the DX9 fix mentioned and it started registering my mouse presses.
However, maybe some kind of alternative challenge method could be considered, in general? Pressing a mouse button super fast like that is really rough on people with CTS.