Hi The Oil Man,
Since you have changed your eBay username, you'll need to generate a new token for your Auctiva account. This can be done at Auctiva -> My Account(Tab) -> Ebay Settings.
For further assistance with this matter, feel free to file a support case using the appropriate link on our help page:
http://www.auctiva.com/free_auction_software_help/help.aspx
-Mike