I'm in the middle of trying that now but the problem I keep coming into is the "Description" of the download which is where the screenshot is has both P and SPAN tags automatically around it without any classes attached to it

Can I get around this by just putting a class on the screenshot itself? So it would look like this:
<span><p><img width="80" height="60" src="blah.gif" alt="" class="classname"/></p></span>