Thanks Ninja.
I can't remember if these spacers came on the factory fender or with the PIAA kit, but as I recall I had nylon spacers that kind of looked like a top hat.
The were white, flat on one side with a smaller diameter on the other, but raised. They fit into the hole in the fender like a spacer and laid flat on the outside. The mounting spacers fit flat against them and all screws were tight. I can only assume the vibrations broke the fender.
Is there any way that you can get a better picture of your install?
Thanks a bunch!