I have a PO box for my mailing address and have completed more than 500 purchases over 4 IDs without a problem . . . . EVER.  There were a couple of transactions where the sellers were insisting on using a courier and I either had the item sent to my wife's work address OR to the local StarTrackExpress depot.  I would recommend to all that a PO Box is the way to go for eBay purchases.

Your followups to feedback left for you have done you no favours.  If I was a buyer thinking of buying from you and I checked out your feedback I would hit the back button and not look at your listings ever again.