Thanks - but no! I've tried all that. It has a 'key captive' feature (i call it a 'monitor') but obviously, when you relock the shackle and turn the key you can't get any purchase on the cylinder as the key can then be removed.
There are two further holes in the padlock but they only give access to the shackle ends (presumably for oiling). Furhter to this, there is this dead wierd 'dimple' thing which seems to be at about the right measurement to hold in the cylinder. Unfortunately; having pressed, twisted and poked it in both the locked and unlocked position, I can't get it to move in, out or shaken all about! Can send a photo of the dimple bit if it helps - it's got to have something to do with it.
