Sid, it is possible the shelf is blocking the action of the bolt work. Also possible a problem in the keylock. Note that on my lock it takes 2 full rotations of the key to retract the boltwork. This is common on many French safes. Also note that on mine the combination lock blocking bar can be engaged in both the extended and retraction positions of the boltwork. So if the main boltwork is retracted and the combination is locked, the key will not be able to make the turns to extend the bolts. From your description, it sounds like this is the situation. So it may be just the spring latch bolt holding the door shut.