I've only had that problem once and it was a couple of months ago.
I do have the odd problem with some international addresses because the program isn't recognizing a part of the address. It won't tell me what the problem is and I have not gotten charged for it in a situation like that. It simply tells me that Paypal is down and to try again. I usually google the address and try to figure out if there is something extra or missing, input the new info and voila..a label.