It seems Windows Vista has a problem connecting Bluetooth headsets that has not been solved yet.
I ran into this when I tried to connect my Acer Bluetooth VOIP Phone to my TM3010. After pairing the device that it recognizes as a headset (passkey 4444), Windows Vista requires drivers. The device appears in the Device Manger as the "Bluetooth Peripheral Device". This also seems to happen with about every other Bluetooth headset that is connected to a Vista RTM system.
According to various newsgroup postings these drivers have been in the product until RC2. But apparently Microsoft removed the headset profile from the product right before RTM. The requested drivers are nowhere to be found yet. The closest thing to a solution is a rather drastic procedure that I found here. It involves removing the Microsoft Bluetooth stack and replacing it by a patched WIDCOMM stack. I don’t know if I am ready for this procedure yet. When I try I will post the results.