I wanted to post my similar issue in this thread instead of creating a duplicate. I feel your frustration as I am having the same problem with my wife's 8310! I have two headsets, Plantronics 330 and a Motorola H500, both of which connect just fine to my Blackjack.
When trying to connect either headset to the 8310 sometimes I will get an "Unable to connect" message and other times I will get a prompt for the headset passcode. After entering "0000" and hitting the scroll ball I will get the same "Unable to connect" message. Here are the "fixes" I have tried.
- Disabled bluetooth>reboot phone>enable bluetooth: Still unable to connect.
- Tried different methods of entering 0000. (carriage return, clicking scroll ball): still unable to connect.
- Made sure the headsets can connect to a different phone.
It seems that there may be an issue with the bluetooth installation on the 8310. I'm all out of ideas. Both headsets are listed as compatible with the 8310. Can anyone please help