Ok, I have just managed (after a long time!) to work out what the problem is -- a bit. I think it is to do with the 'find' button on the base station. I think if this is pressed, it somehow alienates the original handset.(kids!) I fixed this by dealing with it as though it was a new handset I wished to add. (this will only work 3 times so you'll have to make sure whoever pushed the button originally doesn't reoffend...)
1. Push that 'find' button on the base station for 3 seconds until it beeps.
2. you now have 90 secs to do the following:
-press menu
-scroll to find 'register'
-press menu again
-scroll to 'reg base'
-press menu
- select a no which is not flashing (eg 2) (not sure if you have to confirm by pushing menu again here, sorry)
-it will serch...when it connects and needs a pin type in 0000 (unless you have your own pin)
-that should work, hopefully! (For all BT Studio phones)
cheers,
Justine, August 2008