hi i have friend that has a profile hub on his mod but every now and then it gives the occasionally skip, maybe about 3-4 times a week but enough to make him think twice and not trust his bike to do something big. so, is there a way to stop it skipping? can it be fixed? the hub is about 1 month old and was bought second hand, the previous owner didnt use it much so all together its about 3 months old. many thanks JK