Does Mac OS X 10.5.6 break Bluetooth? That’s what some people are saying on Apple’s support forums, as are the jkOnTheRun guys. It seems that after applying the update—I haven’t bothered to update yet—the little Bluetooth icon disappears from the menu bar. Not only that, but the Bluetooth entry in System Preferences disappears, too. Without that, there’s no way to turn on and configure the service.
Don’t worry too much, though, since there is a solution. You’ll need to reset the Mac’s PRAM, which can be done by holding the command, option, p and r keys while it books. That is, turn off the Mac completely, hold those keys simultaneously and turn the power on. The Mac will restart a few seconds into holding all the keys. And then the trees will sing; hallelujah.
You should then be good as new after that.