I just upgraded from 3.02 to 3.0.4. Note that I had to do so by installing the full installation package because the Joomla updater did not work, see my earlier tcket.
Now no comments are possible anymore at all. You can try and test at the supplied URL. Before the upgarde things worked nicely. Now the submit button does not respond at all.
Can you please check? Please note that I can unfortunately not provide backend access to the site.