Von, I did it that way too a few times at first, but from the eBay "PayPal" discussion board, I found out about this better way to do it.

Here is a much better way to use the PayPal postage-shipping label set-up to make a label for a non-eBay-non-PayPal transaction. Use this "beta" PayPal page (the page has been around for years, though you can't get to it from links within PayPal -- trust me. And you might want to log into PayPal before you click this link if you are worried!):
https://www.paypal.com/us/cgi-bin/webscr?cmd=_ship-now

All this can be found in my eBay GUIDE (in this section of the Guide: "MAKING POSTAGE-SHIPPING LABELS FOR NON-EBAY-NON-PAYPAL TRANSACTIONS"):
Introduction to Printing PayPal Shipping/Postage Labels
http://reviews.ebay.com/Introduction-to-printing-shipping-labels-and-postage_W0QQugidZ10000000004429200

[I think it is so --as mentioned in a post above-- that if you use someone else's PayPal payment transaction to edit it so you can ship to someone else, PayPal will automatically send an email notice to the original person (the guy who sent that original PayPal payment). ]

Robert