The developers don't support this application anymore, which means troubleshooting is practically unavailable. I have checked their website, but couldn't find anything related. However, access Quickbooks and go through configuration data. Most likely, this is either an unsolvable bug or a compatibility problem.
You can contact the developers using the information found on their official website: http://www.greatland.com/home.do
Note: Use the Live Chat, because it's faster, but if there is no one online, call them using the number posted on the website.