In reply to Wildabeast:
I wouldn't worry, I'm fat and rubbish and have fallen on and bent mine loads! However, be careful to inspect the slings of your dragons as mine were getting pretty suspect in places at similar age to yours (mainly due to the grit).
I have just sent 7 well used and battered cams back to DMM for re-slinging, much cheaper than buying new cams! 7 re-slung for the price of one about one new cam! I think they pull test them and inspect them before return as well. I'd do this before I retire it if your really unsure.