I have just completed a transaction with PayPal and all went through OK but I find BOAC's post very alarming indeed. In fact, I think I recall having one many weeks ago and binned it. It was certainly asking for account details.
I would have thought that the onus is squarely on PayPal and they should accept that.
I'm on to them now to get a small amount of money in my account transferred to my personal account.
