Are the cases designed to allow the boards to change angle of attack(gybe)from tack to tack? Or have the cases been filled to prevent the boards from gybing? If you bought the boat new, I'd assume they haven't been filled. I think that's what Paul is asking.
I don't know if the Infusion that year had the gybing boards, but I gather they weren't all that popular, and maybe part of the reason is that it was hard on the boards.. Is your damage possibly relatd to stress being put on the trailing edge where it exits the daggerbd case(possibley at different points if the boards were raised to differing levels? Or too fine a trailing edge/poor construction?
Other Infusion owners?

Dave