I've head similar problems with my AKG K81DJ. There, the ear cushions peeled off after about two years, mostly in those places where I had wound the cable around the phones. Might be that the cushions reacted with the softener in the cable's outer sheath.
One a general note: what is this stuff on those headbands and ear cushions? Real leather or just leatherette? Would it help to apply a light coat of a leather care product?
Ralf