Paypal is going to do what is their best interest. I live in Europe now and when I take money out of my US bank account, it takes a few days before the transaction hits my account. No matter what xe.com says when I withdraw the money, somehow my bank finds a lower exchange rate when it takes the money from my account.
But anyway, you did find the solution. Don't transfer money between banks in a foreign currency and not expect to get shorted.