Help-PB G4 12" Sleep Problem

[Zaty]

This morning my PowerBook G4 12" ceased going to sleep automatically. I tried different settings in Energy Saver and reset the PMU twice to no avail. I also disconnected everything. Putting it to sleep manually works fine, though. Any ideas what could be wrong?

Thanks Zaty

Edit: I'm running 10.3.3 + the latest security update.