A few errors. In your template, change
PHP Code:
<applet codebase="$vbulletin->options['bburl']/irc/" code="IRCApplet.class" archive="irc.jar,pixx.jar" width=640 height=400>
to
PHP Code:
<applet codebase="irc/" code="IRCApplet.class" archive="irc.jar,pixx.jar" width=640 height=400>
Also in the version I was coding, I added a new permission "group" to the Usergroup manager so you didn't have to put the usergroup numbers allowed. I will send you my code for that and I made another file irc.php so it didn't have to conflict with misc.php.
The template also needs to be formated correctly also.