You can make changes to your re-list from Auctiva (title, a lower starting price, duration, add images, etc.) and still be eligible for the relist credit on eBay. Here's a link to some of eBay's tips for relisting: http://cgi5.ebay.com/ws/eBayISAPI.dll?BetterSeller
Of course, I'm sure there are some other guidelines that need to be followed to get the credit (for instance, you can't take an unsold listing and change it into a totally different one to get the credit.) If I find more info I will post it here....good luck!