abar

so i have been riding a fixed gear conversion for the past 8 or so months and in the last couple of weeks i have issues with my chain or hub slipping. i can't recreate it unless i am trying to skid or push up a really steep hill. my commute is relatively hilly and it always when descending or ascending those hills. so far i have replaced the chain and the chainring and the guys at the shop seem to think that my chain tension is fine as well as my cog.

has anyone heard of iro hubs stripping that would cause this? because i can't imagine the chain doing it after all the stuff i have changed.

thanks