I know Auctiva is aware of this, but for some reason they haven't let the masses know.
People, when you go to your Sales page on Auctiva, be aware that you may see duplicate line items. I almost sent additional items to a buyer of mine, until I realized the fault was with Auctiva's website. Look carefully at your line items underneath each of your buyers. If a buyer is getting more than one item, make sure there are no duplicates. The best way to tell is to double check what you see, with eBay. eBay is accurate. Auctiva is not.
Buyer "fred" won some balls. On his Auctiva packing list it says he's to get 2 green balls, 3 red balls, and then it says 2 green balls again. Double checking on eBay shows he's to get a total of only 2 green balls, not 4.
Sometimes I'll have buyers buy the same item twice, so Auctiva's packing list "could possibly" be correct, but there's no way to tell unless you compare it to what you see on eBay.
Again, I don't know why Auctiva hasn't posted an alert in this regard, for something so important.