ibook won't wake up

[milo]

I'm running OSX and when it goes to sleep, it won't wake up. Just started happening yesterday. I don't understand why. Any ideas?

[stimuli]

Won't wake up as in... Screen is blank, but disk is spinning? The iBook is still asleep (the light pulses)?

[equitek]

I have that happening sometimes to my Powerbook G3 Series. It will go to sleep normally, but when I wake it up it will appear to be waking up, but the screen will stay black and no sound. The machine IS awake though, because I can hit the power key and return and it will turn off gracefully, then I can turn it back on and all will be well. On that machine it happens about 75% of the time, and it never happens to my new iMac, or my blue "toilet seat" iBook.