I use both as well and never had a problem with it. What version are you using Wally? The old version I was using I believe was 1.6, but I have upgraded and now am using 2.0. The reason I upgraded is because I was having graphics problems (the screen being skippy) in window mode of Cod4, that didn't fix the problem but I believe now the problem is caused by Window's aero effects. I turned them off and all is good now, back to your post I have no clue what's causing this, I would upgrade to the latest version or maybe assign MSI admin rights to run, see if that helps.