i don't really know the secret of it to be honest.
it was lot of trial and error
my BT dongle is the belkin F8T008 and i'm using widcomm version 5.x drivers
also the sound wasn't working until i tried it for the first time with Mobile Impact (front end)
have you run the wizard for phoco?
the best idea is to just get phoco and the phone working first rather than takling front end integration