Ok, I have played a little more and attempted to manually update the
driver from the bcbthid64.inf and btaudio.inf files contained in the package, and neither the "Bluetooth Hands-free Audio" or the "Bluetooth Hands-free Audio." models appear to work.
I am guessing this is an x64 problem as the x86 RC I am using on another machine works out the box, with no messing about.
Is there anything else that I can do? I had similar problems with Vista prior to SP2 and ended up replacing the Bluetooth stack to fix it, I do not want to end up doing that again.