Okay, that took only 5 minutes
in /scripts/viewmessage.inc.php
find:
$user['USER_TOTAL_PM'] = $total_unread;
Add below:
$island_insert = get_portal_box("portal_box_3.php");
You can replace that number 3 there with any of the other custom boxes. It's hardcoded for simplicity of the hack. No sense in make more fuzz of it then the 2 line hack it is
Just under it find
"online_status" => $online_status,
Add below:
"island_insert" => & $island_insert,
And yes, that's all there is to it.
It's a really simple hack, you just have to provide the $island_insert variable to the smarty template, and it will be displayed automaticly below post #1.