Bluetooth and Lion

I'm having trouble in getting my Bluetooth headset to work under OS X
Lion 10.7.4 running a 3.33GHz Intel Core Duo 24" iMac with 4 gig RAM.
It ran perfectly under OS 10.6.8

I checked on the Internet and from the Apple Support Forum found a list
of instructions that could help.

I've tried them all, but none work. They include disconnecting all USB
devices, repair disk permissions, delete the prefs file for Bluetooth
and restarting, and finally resetting the PRAM on the Mac.

As I said, none work.

Has anyone got any further suggestions that might help?

Peter

--
It is necessary for the good man to do nothing for evil to triumph.

Attributed to Edmund Burke 1729 - 1797
.