fuel filler flap not unlocking on 2003 ML - any ideas?!!

[philcray]

Stopped to fill up the ML this morning and the filler flap did not unlock. Despite locking and unlocking the car a few times, I could feel that the pin was still holding it closed. I did not want to break anything so didn't force it but I wondered if anyone else had had this problem? Luckily I was not running on empty so have some time to get it opened before it gets desperate!

Cheers

Phil