[SLE] Strange mouse behavour.

I'm running 10.1 on an HP dv8000. I sometimes get some strange behavour that seems to relate to mouse movement. For example, I bring up the start menu and select shutdown. The shutdown window pops up with the various options (shutdown, restart, etc). When I move the mouse over to the window, it dissappears when the mouse pointer touches it. If it try it a few times I can eventually get inside the window to select a option. Also, if I navigate around the window and enter it from the right side to get to the buttons, it works OK. Anyone seen anything like this before? Thanks! Doug