I have a 3 drawer pedestal that won't lock. When the key is turned in the lock it feels as though the lock doesn't quite catch on whatever it's supposed to. The mechanisim is similar to the pedestal lock in the first picture here: http://webdev.anagi-publishing.co.uk/stockfit/html/locks.htm#marker1. It has a lock bar & catch inside which appear to drop down when the key is turned. Is there any way I can stop this happening? BTW - bar & catch are both intact.

Any suggestions greatly appreciated.

Thanks