Disappearing mouse cursor

I'm running KDE under SuSE 10.0. Sometimes when I've left the computer running for a while by itself and the screen saver comes on, I come back and discover that there's no mouse cursor. I don't see any pattern to when it happens and when it doesn't. So-- 1. Is there anything I can do less drastic than Ctl-Alt-Bksp (which works) to get the cursor back? It clearly must be something that I can do from the keyboard alone. 2. What is likely to be causing the problem? Paul