I spoke with Live Support at eBay...all the guy could do was file a ''trouble ticket'' with tech support.
My eBay ID is turtlechickbeads...you can look at my listings and see the shipping discount I offer at the bottom of my BIN's....but no such thing in the auctions. The ONLY time the discount is auto-applied at checkout is for multiples of the same BIN item.
Weird and aggravating problem!