In newest Ubuntu precise betas Bluetooth is broken. Steps to reproduce: - switch off Bluetooth using the indicator - reboot - switch on BT using the indicator - BT does not actually switch on, it remains off (though on some rare occasions it will work just fine) - if you try to enable BT in control center, it either will not activate or switches itself off almost immediately - if you reboot after switching on BT in the indicator, it will start working again I'm not entirely sure when this bug appeared, probably somewhere between 3.0 and 3.2. This behaviour is the same with Ubuntu kernels and upstream kernel 3.3.0-030300rc7. This happens on two different machines: a desktop with a BT dongle and a Macbook Pro with a built-in Broadcom BT chip. This bug was originally filed as https://bugs.launchpad.net/ubuntu/+source/linux/+bug/952917,
It seems to be fixed in 3.7.1, on Debian Sid.