[Lynne]

Maybe it's not the style - maybe something else is wrong on your board. Have you looked in the error_logs? (If you don't know where they are, ask your host.) If no dropdowns are working, it sounds like you turned off dhtml menus (vboptions > style options). Have you tried disabling your plugins and seeing if that fixes things?
Note: To temporarily disable the plugin system, edit config.php and add this line right under <?php

PHP Code:

define('DISABLE_HOOKS', true);