Sime46 - maybe take time to read my initial post before saying I am being unfair. I clearly say one of my breakages it my fault. The other two I feel are not.
Adam/Chris - Yes you are exactly right, I should have explained in my post. This happens after jumps, and it will be due to limited uptravel (although not because of spacers - I didn't have any in the front - it is limited enough under standard setup).
bigred - The shock is/was free moving on the shock tower, thanks for the idea though.
ryan - Glad I am not the only one
dcm - Good thinking about another wishbone. What makes you suggest Tamiya? Is it strength/impact resistance? Something I think I might look into.
I think the rest of the wishbone is indeed very strong. When this breaks, like in my photo, the rest of wishbone is fine, it is just the shock mounting that comes off. This hasn't been crash damage, I have crashed my cat sx plenty and can ensure everyone it is strong enough hitting stuff and I have only broken one wishbone in a crash.