I was given a Sony Ericsson Stereo Bluetooth Headset (can't remember the model number of the top of my head) for Christmas and I have been having problems getting it connected to my i8510.
If I start with a clean install it pairs fine but I have to disconnect via the phone i.e. I must go into the Bluetooth option in the phone menu and select disconnect, if I disconnect any other way when I try to re-connect it will not work.
This only becomes a problem when you let the headset disconnect (i.e. because you are too far away from the phone) and then try to re-connect, this happens to me mostly when I am in the car and need to pick up a call and can't. ...very frustrating
The only way to resolve the issue seems to be to delete the pairing and start again.........all very time consuming. I also see this problem with my Parrot MiniKit