I just thought I would let you know that you checkout is not working correctly. If you try to check out and create an account on the fly it always tells me "Billing Address incorrect". I mean I have no idea what kind of error check you would perform on the personal address of somebody, but in any case I'm pretty sure I remembered my address just fine .
Now I fell in love with Black Ink on first sight, so I was persistent enough to find out that it works when I create an account FIRST and then check out, but my experience with online shops tells me that 90% of all customers that experience that problem will leave and never come back. So better take a look at it.
Best
Florian