I've had 0 luck with my DUO and N800, it pairs but yet they never connect or see each other after pairing, so that goes for tethering as well.

I've got posts here, Howard Forums, ATT, and the XDA developers site. No one seems to know why they won't see each other.

And I have no probs with my BT keyboard on the N800 and a BT headset on the phone side.