I found a way to "ressurect" the screen after it goes into stand-by:
- (force a stand-by running xset -display ":0" dpms force standby in a shell)
- After the monitor switches off, press Ctrl+Alt+F1
- Press Alt-F7
And the monitor turns on.
I just don't see why it doesn't come up when the user presses any other key or the mouse/touchpad...
I am running SuSE 10.0 (kernel 2.6.13 and Xorg 6.8.2).