Ah, fixed it myself.
Here is what to do if anyone else has problems:
Open the file 'forum' and replace:
PHP Code:
$threadbits .= "<li /><a href=\"$archive_options[archiveurl]/$archive_options[topicfile]/$thread[threadid]-1.html\">$thread[title]</a></li>\n";
with
PHP Code:
if (!($forumperms & $vbulletin->bf_ugp_forumpermissions['canviewthreads']))
{
$threadbits .= "<li />$thread[title]</li>\n";
}
else
{
$threadbits .= "<li /><a href=\"$archive_options[archiveurl]/$archive_options[topicfile]/$thread[threadid]-1.html\">$thread[title]</a></li>\n";
}