im haveing the same problem, it happens wen your middle seatbelt tensioner jams. safety.
i think the only way to get it out is take the trim in the boot around it off. there is a rod that it is cathing on, take the bolt holding the rod to the car out and the seat will pull forward. you may be able to move the latch at that stage buh if not then take the seat out and then strip the seat down and u will see inside the wee catch for it. if you just push it over with your finger it will work again releasing the rod and bolt the rod back on.
also if your seatbelt tensioner is stuck you will need a new one. its better to replace it wen its down. its not a hard job to do
Conor
January 2010