[Lynne]

So because it is in hebrew, you can get away with going <font color='red> instead of <font color='red'>? That is very strange and doesn't seem right, but if you say so....

As for whether it is the template, create a new style with no parent - Styles & Templates > Style Manager > Add New Style > no parent - then browse the site using that totally default vbulletin style - are the usernames correctly marked up then?

And for whether it's a modification, try disabling your plugins and see if you still have this problem.
Note: To temporarily disable the plugin system, edit config.php and add this line right under <?php

PHP Code:

define('DISABLE_HOOKS', true);