Well it seems that it happens more than I thought. I'll ask the old metho swilling LAME bloke who looks after it when I go past next time and try to get some more details. It's not my plane, I just fly it for a mate occasionally. The way they slammed fully up suggested to me that there is some some of overload on whatever part of the mechanism holds them down for landing because they really banged up hard but worked fine ever since. He'll do what he does for everything that comes his way. Blame the pilot for doing something wrong..... "everyone knows that when you put the flaps down in a "j" model on a day starting with a "T" that you should whistle the sound- track to MASH as it goes through flaps 30 you useless wannabe young idiot!!!"
Thanks for the replies guys.