Thanks for the reply, I sent the file to your team to take a look.
The only other thing I can think of is that everything is already being moved via another path constraint, so this is a path constraint on top of a path constraint. That seemed to also mess up IK based on a bone that was constrained to that original path. I gave up IK in favor of manually animating my paths. That at least has the appearance of working until this export problem.
edit: I just confirmed that changing the parent of the bones that I am moving with the path fixes the mesh issue. The problem is that now I have to manually animate them instead of getting the position of the bone they should be attached to.
I believe this to be a bug though, unless thee is reason not to be able to have a path constraint based on a bone that is already being moved via a different path constraint.
