If we say that mtGox takes 2%, then we have 3.5% left unaccounted for. I suspect these are the fees that the banks have taken when converting currency. I do not know if mtGox charge anything for converting currency.
That sounds typical for a currency exchange done by a bank. Why do you think the rest of us are working to make Bitcoin succeed?
I'm with you all the way, I'm working towards this myself. We all wants fees to go away.