Since I installed the 10.4.4 update, I've noticed that my Bluetooth doesn't work correctly. Given time, it'll indicate being turned off and the option to turn it on is grayed out in both the menu and in System Preferences. Restarting blued has no effect. The first time, a simple reboot fixed the problem, but then it came back (after sleep and wake, I think). An hour ago, I rebooted and reset NVRAM, and so far it's fine, even after testing sleep, but I can't guarentee anything. I'll post back if it breaks again.
(I have a PowerBook G4 12")