add a tab in the users page

hello. I want to add one tab in the users page, in this tab i want to show some information from buddylist module.
The problem is that users only can see his/her own tab, but not other users tab. I'd like that users can see other users buddys activitys

<?php
/**
 * Implementation of hook_perm().
 */
 function buddysactivity_perm() {
  return array('my buddys activity');
}
/**
 * Implementation of hook_menu().
 */
function buddysactivity_menu($may_cache) {
  $items = array();
  if ($may_cache) {    
	 if (arg(0) == 'user')  {   
			 $items[] = array(
			 'path' => 'user/'. arg(1) .'/buddy',
			 'title' => t('my buddys activity'),
			 'callback' => 'my_buddy_activity',
			 'callback arguments' =>array('user', arg(1)),
			 'access' => user_access('my buddys activity'),
			 'type' => MENU_LOCAL_TASK,
				);	
		}
	}
    return $items;
}
/*
 *
 *submit de la información.
 *
 */
function my_buddy_activity (){
	$pared = '<div id="pared"><ul>';
	if ((arg(0) == 'user') && is_numeric(arg(1)) && (arg(2) == 'buddy')) 
	{ $arg1 = arg(1);}	
	$query="SELECT a.buddy, u.name, u.picture, n.created, n.title, n.nid, n.status 
		  FROM {users} u, {buddylist} a, {node} n 
		  WHERE u.uid = a.buddy 
		  AND a.uid =%d 
		   AND a.buddy = n.uid 
		  AND n.status =1
		  order by n.created DESC"; 	
	$result = db_query_range($query, $arg1, 0, 30);	
  while ($data = db_fetch_object($result)) {
    $pared .= '<li>
			<a href="'.base_path().'node/'.$data->nid.'" alt="'.$data->title.'" title="'.$data->title.'">
			'.$data->title.'
		</a>'.  t('by') .' <a href="'.base_path().'user/'.$data->buddy.'" title="'.$data->name.'" alt="'.$data->name.'">'.$data->name.'</a>';
  }
 	$pared .= '</ul></div>';
	return $pared;
	}
?>

Also, i'm using also bio node in user page and i18n, but I thinks this is not the problem.

Thanks

Oskar