I was receiving the error , "headset has been disabled by your system administrator." on my BB 8830 with BES. Solution on my end turned out to be as simple as going into the BlueTooth application on my BB --> bring up MENU --> OPTIONS --> Scroll down until you see SERVICES: Check the box next to HEADSET which was previously unchecked. The default is for the service to be turned on. In my case I was troubleshooting using the phone as a modem and in that process turned this off.