OK I see the issue. The problem is invalid HTML. The <FORM> tag is opened first, then <DIV class="qa-q-view-main">. But then we have </FORM> before all the divs are closed, the following comes after the form tag: </DIV> <!-- END qa-q-view-main -->
Not sure exactly why this is happening, as I thought the HTML was output from the theme cleanly and in a modular fashion.
Edit: another HTML error is the use of <SPAN CLASS="entry-content"> for the post itself - which contains many <P> tags (with the WYSIWYG editor at least), which is not allowed in HTML (block tags inside inline tags).