Index: wp-admin/includes/class-wp-users-list-table.php
===================================================================
--- wp-admin/includes/class-wp-users-list-table.php	(revision 19681)
+++ wp-admin/includes/class-wp-users-list-table.php	(working copy)
@@ -64,10 +64,19 @@
 		if ( isset( $_REQUEST['order'] ) )
 			$args['order'] = $_REQUEST['order'];
 
+		if ( $this->is_site_users )
+			switch_to_blog( $this->site_id );
+
 		// Query the user IDs for this page
 		$wp_user_search = new WP_User_Query( $args );
 
+		if ( $this->is_site_users )
+			switch_to_blog( $this->site_id );
+
 		$this->items = $wp_user_search->get_results();
+		
+		if ( $this->is_site_users )
+			restore_current_blog();
 
 		$this->set_pagination_args( array(
 			'total_items' => $wp_user_search->get_total(),
@@ -86,10 +95,12 @@
 			$url = 'site-users.php?id=' . $this->site_id;
 			switch_to_blog( $this->site_id );
 			$users_of_blog = count_users();
+			$roles = wp_roles->get_names();
 			restore_current_blog();
 		} else {
 			$url = 'users.php';
 			$users_of_blog = count_users();
+			$roles = wp_roles->get_names();
 		}
 		$total_users = $users_of_blog['total_users'];
 		$avail_roles =& $users_of_blog['avail_roles'];
@@ -99,7 +110,7 @@
 		$class = empty($role) ? ' class="current"' : '';
 		$role_links = array();
 		$role_links['all'] = "<a href='$url'$class>" . sprintf( _nx( 'All <span class="count">(%s)</span>', 'All <span class="count">(%s)</span>', $total_users, 'users' ), number_format_i18n( $total_users ) ) . '</a>';
-		foreach ( $wp_roles->get_names() as $this_role => $name ) {
+		foreach ( $roles as $this_role => $name ) {
 			if ( !isset($avail_roles[$this_role]) )
 				continue;