About the <img> tag

Today when I want to create a feed for one of my site with feedburner,error occurs,said Error on line 86: The element type "img" must be terminated by the matching end-tag "</img>" .But I didn't see anybody use the img tag like that.Anyone can explain it?

I thought <img src="your img path"> works in html
And <img src="your img path" /> works in xhtml,you had to tell the browser you have closed it
Your problem could be what they are using is xhtml,not html

That is very strange. If I know correctly then <img> tag does not require </img> for closing.

By the way why should you need <img> tag for creating feed url. Only website URL is needed for that.