Some users have reported a loss of Bluetooth connectivity after updating to Mac OS X 10.6.3. Users who experience this problem find that the bluetooth icon on the menu bar has line through it (indicating that it is not operational) and displays the message ‘Bluetooth not available’ when clicked. The Bluetooth pane may also be missing from System Preferences.
Delete Bluetooth .plist file. Look in both /Library/Preferences (the library folder at the root level of your hard drive) and ~/Library/Preferences (the library folder inside your user folder). Delete the file com.apple.Bluetooth.plist from both locations then restart.
Reinstall Mac OS X 10.6.3 combo updater. Download the Mac OS X 10.6.3 combo updater, which weighs in at a hefty 784MB but is a troubleshooting godsend. Quit all open applications and run the installer.
Reset PRAM/NVRAM. Reset your Mac’s PRAM and NVRAM per Apple’s instructions.