[Xenon]

run this query:
[sql]UPDATE user SET avatarid=x WHERE usergroupid=y[/sql]

replace x with the avatar id of your banned avatar and y with the banned usergroup id.

and to do that automatically in the future:

open mod/user.php
find this:

PHP Code:

    $DB_site->query("UPDATE user SET usergroupid=$bangroup[usergroupid], customtitle = 0 , usertitle='".addslashes($bangroup['usertitle'])."' WHERE userid=$banuser[userid]"); 


and change it to:

PHP Code:

    $DB_site->query("UPDATE user SET usergroupid=$bangroup[usergroupid], avatarid=x, customtitle = 0 , usertitle='".addslashes($bangroup['usertitle'])."' WHERE userid=$banuser[userid]"); 


replace the x with the avatarid