I have what I hope is a really unusual but easy to solve problem. I left my PowerBook unplugged by accident for several hours and when I got back the battery was depleted. What was unusual was that it was actually off, rather than simply asleep. So I booted up, and to my shock, the Bluetooth menu extra says "Bluetooth: Not Available" and the Bluetooth System PrefPane has disappeared. When I went to About This Mac to get to the System Profiler to see what it had regarding Bluetooth (nothing), I saw that the system was only registering 512 MB of my 1 GB of RAM. Further inspection in System Profiler revealed that one of the slots was "empty", though in reality both are filled with 512 MB each. Has anyone seen anything like this before?