David, when you want to reply to a users comment or question please click the little reply Icon at the right corner of their message box.. this will Highlight your comment and it will send your reply to their email address as well.. when you comment the way you did , they dont know you responded unless they come back to the auction.. ;)
I would suggest you add a picture to your auction, you can contact the help page and they can help you.. it would make a huge difference in your auction I think. :)