[CarCdr]

Actually, I see now that one needs to make the change I suggested at the top of the script. In newattachment.php, around line 50, you'll find this:

if (!$bbuserinfo['userid']) // Guests can not post attachments
{
print_no_permission();
}

AFTER this code, add the code I suggested:

if (is_member_of($bbuserinfo, '6')) {
$vboptions['attachlimit'] = 8;
}

using the usergroup you need (I used '6' here) and the attachment limit you want (I used 8).