From Brett Gaitley
I had a SF field mapping called CurrencyIsoCode that was mapping to our currency field in NS. Everytime it synced over, it synced over completely wrong information. Simple fix, I just download the currency for all customers from NS and batch upload in SF. But then, there is no field in SF called CurrencyIsoCode. Can't fix what I can't find. There is an account currency in SF, but that field isn't one of the options to sync.