What would cause the lock on my center box on the tank stop working? I took it apart (with great difficulty since it was locked and button would not depress but key turns easily from side to side!) i finially kind of popped the lid open by flexing it a little which let me get to the screws and remove the cover plate. The lock cylinder came out easy enough and the lock bar retracted to the open position. The lock will turn with the key rotating a rectangle end but will not depress at all! The retaining lock bar also will not now clamp to hold the ld down. Any ideas? Just had the battery replaced by the dealer under warranty it went bad in a month but that is another story! Lol. Got it back home and lid would not unlock. No problems before this.