I'm using Word 2007 and my boss is using Word 2010 and we have the same issue. We have several documents that have Track Changes turned on & there are several changes within each document. When I move the mouse pointer from the track changes bar on the righthand side of the screen to the middle of the screen where the document is, a black box appears over most of the screen & I can't see the text underneath. If I scroll down, the box goes away, but if I move my cursor in the same way, it comes back. I've heard it may be a "video issue." Not sure if I agree with that, but if so, what kind of issue and how would it be remedied? If not - help!