Not quite sure what you are asking.
However, looking at your forum (once I got the right link) it looks like you have modified the header.asp file and have changed the link to the forums javascript file. This is coursing drop down boxes and AJAX to not work.
In your forum it is:-
<script language="javascript" src="includes/default_javascript.js" type="text/javascript"></script>
It should be:-
<script language="javascript" src="includes/default_javascript_v9.js" type="text/javascript"></script>
The file name was changed in version 9 to have _v9 in it as IE had a bad issue of caching the javascript file and not loading in the chnaged file when upgrading from previous versions.