Used to get the same problem with pairing having to be deleted with the T68i.
Problem was fixed by removing the pairing on the Aircable as well.
You do this by pressing the reset pin and keeping it pressed for 5 seconds.
After that, remove and replug Aircable back in. Not sure if you need that bit.
Delete any pairing on the phone as well, and then pair again. Make sure you use Phone Accepts and not Phone initiates.
Don\'t actually have a 610, but as they are both SE and I had the same problem, chances are it is the same thing.
Another option if all else fails is to simply bin the pairing on the phone side all together. This works on the T68i, not sure if ption is available on the 610.
Instead of pairing, just set phone to discoverable then when you get the options to Accept or Accept and pair choose the first one.
It means entering 1234 everytime, but less hassle than deleting pairing.
Let me know how it goes.