Thanks for your help LifeisLike and Mike D.,
Yes, for some reason the culprit in all this wasn't an expiration date issue but the PayPal link just dropped off as a payment method. Just like Keyser Soze...Poof! It was gone! :-) Very interesting how that happens! No worries, we fixed it/re-linked it this morning and I'm back to posting items just fine and dandy thru Auctiva to eBay. Both your advice certainly helped us find the problem pretty quick -- and, of course, your input was very much appreciated!
Have a great day to you both and thanks again for your help in this matter!
Sincerely,
Jeffrey