I had this problem just as described but also afterwards, at the second checkout. That is, after closing rythmbox and logout I manage to have the first checkout. A couple of hours later, still logged in, I went for a second checkout and the store hanged at the connection screen. After log out of the dashbord, restart rythmbox, checkout works again. Oh, by the way, I think the basket should not become empty after a failed connection at checkout.
I had this problem just as described but also afterwards, at the second checkout. That is, after closing rythmbox and logout I manage to have the first checkout. A couple of hours later, still logged in, I went for a second checkout and the store hanged at the connection screen. After log out of the dashbord, restart rythmbox, checkout works again. Oh, by the way, I think the basket should not become empty after a failed connection at checkout.