Jeremy quite literaly that is the HTML coding and not this hack for the short answer. I beleive that is your tablesurround on the Threads TBOPEN AND TBCLOSE variables. Match that color and see. Try modifying your variables in tbopen.tmpl
The class for the menu and menu2 variables is set in pp-inc.php and thus has no tbopen and tbclose tags around it and will not do this. Hense you notice that border is around any table that calls the wrappers.
