I was out last night and when using my Baader Hyperion MK III 8-24 Zoom EP I found that it had jammed - it turns between 8 and 12mm but I can't turn it back any further than that. I've had a look at it this morning and can't see anything visibly wrong with it but it really is stuck - anyone had this problem? I'm a bit loathe to take it to pieces - if I'm honest I don't even know HOW to take it to pieces! Any ideas/ advice?