screen flicker after waking from sleep


On my powerbook g3/233 (Wallstreet, 288Mb) I'm suffering from a flickering screen after the machine is woken up from sleep mode. The longer the machine has been in sleep mode, the worse the flickering is. Gradually the flickering becomes less again until it is completely gone. I've experienced this problem already with the public beta, and now with 10.0.3 it is still there.
If I reboot into OS9 directly after waking up the flickering is still there (but goes away as well the same way as under OS X).

Has anyone else experienced this problem, and even better, a solution for it?