I think that even if they haven't paid you can go to print a label and on the page as if you were printing a label, where you enter the weight of the package and such, it should say if the address is confirmed. I Think. I could be wrong but I would be curious to see if it says it is confirmed on that page.
Ustream Channel: http://www.ustream.tv/channel/dthimesch
Vaughntv Channel: http://breakers.tv/dthimesch