Thanks for these pictures Peter, I understand what you were saying now. I've taken off the mechanism to get to the pawl and I can see the Achilles heel now, the pawl just slips when trying to engage with the gear. Check the picture below for the condition of the pawl, I can't see exactly where damage has been caused but it does seem really small. The only other thing I can see is that my spring is attached differently to yours, I don't know if that's significant? But I suppose there's not much that can be done without fixing the pawl as you have...