I initially thought that maybe the barrel was broken, but after getting the barrel out and seeing that the key is working fine in it i know it's not. The next thought is that the alignment is not quite right, the key locks the door but just won't get far enough so that it can be taken out leaving the door locked... any advise would be greatly appreciated

broken door, February 2009

The door may need ajustment on the hindes or the locking mechanism on side of door/frame may need aligning (assuming the door has multi point lock)

Michael A, February 2009