If I leave my Powerbook alone while it's streaming music to my stereo via an Airport Express (which I do a lot in my no-physical-music-media flat) then, once the display has gone to sleep and the screensaver has come on, I can't get the machine back - moving the mouse reawakens the screen, but all I get is the spinning-beachball-of-doom. This isn't a crash or full system hang per se: iTunes keeps on doing its AirTunes streaming thing quite happily, but the machine does not come back from screensaver land.
If I then sleep the machine, wait for a bit, and then wake it I'm left in the same position: The only way out seems to be to do a force shutdown and restart.
Has anyone else seen this? Are there any workarounds?