I’ve found only one other reference to a problem like this through google, and no one was able to help that person.
If my Vista login screen goes to its screen saver, then when I end the screen saver, my mouse’s cursor is not visible. It’s there, in the sense that by moving the mouse I can highlight things and click to select. But the cursor is not visible.
I thought about maybe reinstalling the mouse driver, but in the hardware profile for the mouse the buttons dealing with the drivers are greyed out.