LaLeLu, sorry if You feel offended, but read my posting again.
I tried to be a litle more diplomatic this time,ref gear oil, but that was wasted.
If you want to see what may happend to a one year old propeller, have a look at my web page: http://www.geocities.com/haffiman37
and read about the Gori 3-blade and my experiences with that one.
It seems to me clear that who ever surveyed your boat missed the corrosion on the strut, probably because it was all covered up by some years of anti fouling. If your boat builder have never experienced a strut failure with that design they have been lucky! With a casted bracked, stainless steel bolt and welded flat metal strut and no anode? It is just a question of time before a thing like that would happend. Note that the shaft anode do not protect the strut, that one is isolated with the rubber in the cutlass bearing. My reason for asking about yearly service was that I did not see any traces of grease anywhere. Either someone has used a bad quality of grease or there has been no service! If I am affiliated with Autoprop? Read my previous posts about my preferred propeller type! Why my interest in this? This kind of breakdowns and analysing has been my way of living for quite some years. Too often I have seen people repairing what have been broken without finding the real reason for the breakage, and I am quite concerned about safety at sea. If I find 'bad' products i go after the manufacturer, however in this case I think You are barking up the wrong tree!
It seems that I am not quite alone in my evaluation of the reason to the damage.
Unfortunately the problem is still Yours, but do not shoot the messenger that will not help You much in the future. This is not personal, for me it is pure professional and technical!!!!!!!!!!!!!!!!!!!!!!!!