I have encountered this acouple of times. When I right click, the context menu pops up, but the menu items are missing until I move my mouse over them. I've checked my system resources (this is WinXP by the by) and my cpu usage hovers around 4%, and I have about 230MB out of 512MB free. Usually a restart resolves this issue though, but how do I keep it from not happening? (i.e. what causes this to happen?)