This happened to me yesterday. My handset would not communicate with my HS 810. I deleted the HS 810 from the 7100 and tried to pair but the BT on the phone would not work. I then turned off the phone BT and the 7100 got stuck in an hourglass loop. I held down the power button, rebooted, turned on the BT and paired the devices. It works fine now, but there is a glitch somewhere.
I still am very happy with the 7100T. It is exactly what I needed in one device.