Sometime my pass. door lock will not unlock. Ill go to pull on the poll at the top of the door and it wont budge. Ill get out and use the key and just work the all living heck outta my hand and it stays locked. Finally it will give and unlock.... It doesnt do this all the time but it usually happens at the most unconvenient time Seems like something is hanging or catching not allowing it to unlock. What is causing this and how can i fix it?