This has happened to me with a single account and was told by support that it was due to a synchronisation hiccup between eBay and Auctiva.
Still happens to me occasionally, however the multiple images always link to the same listing. The down side is that it does waste limited image 'slots' which could be used for other items.
I suggest you file a support request with Auctiva to get these 'ghosts' exorcised as you cannot correct it yourself.