Ah, the dreaded in-dechiperable 'something's up' error from PayPal.
I have a test account (redwineaudio.foxycart.com) with generic WPP setup and default gateway.
I'm trying to get through to the receipt page so I can do style it but I never get past the error message:
"There was an error processing your payment: (10001 Internal Error) Internal Error'
I'm using the 4242.. card number.