I just discovered a fault in Ebay's shipping system. Apparently the system will allow you to select UPS or FedEx as the carrier even if the buyer's address is a PO Box. UPS and FedEx do not deliver to PO Boxes, so this means you package will be in limbo until the carrier returns it to you. This seem like it would be a fairly simple software fix to not even offer these two carries when the address is a PO Box.
