Two of my layers have straight up stopped being susceptible to automatic flexi binding, and I have no idea why. The anme file is up on my onedrive here:
http://1drv.ms/1EUcYFe
If somebody could take a look it would be hugely appreciated. I'm stumped and losing my fighting spirit.

L arm and R arm are the layers concerned. The rest of the character behaves a bit oddly, too, but as long as I know what's wrong with R arm and L arm I think I'd be able to fix all of it.