I had exactly the same issue when I tried donating and I ended up putting the same data into address fields as they are on my credit card. I tried contacting the given email address, posted in this very thread, and even Joerg_rw himself became interested in the issue, but somehow (I guess due to my impatience and their busyness at the time) I ended up just redoing the order with slightly different address (the old one got cancelled automatically 2 weeks later or so) which resulted in success It would be really great if the webform could accept different addresses for the credit card owner and for the invoice/shipping, as we apparently both suffer issues from the fact that they are being different.

Edit: sorry for oftopic, just wanted to respond about my experience with similar situation