My modified version is pasted at http://pastebin.com/hQnShaxA

My modified version:

<?php
 
/***
* Menu WALKER - for restricting the menu items visibility
* Code modified by - Trupti Bhatt (http://3sided.co.in)
* using original code posted here - http://www.tisseur-de-toile.fr/wordpress-tricks/pimp-my-wordpress-menu-part-2-access-granted-to-authorized-personnel-only.html
***/
class description_walker extends Walker_Nav_Menu
{
        /*
                 *      Custom var to store current role
                 */
                private $current_user_role = "";
               
                /*
                 *      Get te current user role
                 */
                private function getCurrentUserRole()
                {
                                global $current_user;
                                if ( is_user_logged_in() )
                                {
                                        if ( $this->current_user_role == "" )
                                        {
                                                $this->current_user_role = $current_user->roles[0];
                                        }
                                       
                                        return $this->current_user_role;
                                }
                                else
                                {
                                        $this->current_user_role='visitor';
                                        return $this->current_user_role;
                                }
                }
               
                /*
                 *      Check if the user is an administrator
                 */
                private function isAdmin()
                {
                                $current_role = $this->getCurrentUserRole();
                               
                if ( $current_role == "administrator" )
                                {
                                                return true;
                                }
                                else
                                {
                                                return false;
                                }
                }
               
                /*
                 *      Get all restrictions
                 */
                private function getAllRestrictions()
                {
                        global $menu_restricted_access_array;
                               
                       
                                $all_restrictions_array = array();
                               
                                foreach ( $menu_restricted_access_array as $one_restriction )
                                {
                                        $all_restrictions_array = array_merge($all_restrictions_array, $one_restriction);
                                }
                                $all_restrictions_array = array_unique($all_restrictions_array);
                               
                                return $all_restrictions_array;
                }
               
                /*
                 *      Check the access
                 */
                private function isAccessGranted( $id_menu_item )
                {
                                global $menu_restricted_access_array;
                               
                if ( $this->isAdmin() )
                                {
                                                return true;
                                }
                else if ( isset($menu_restricted_access_array[$this->current_user_role]) )
                {
                    $restricted_access = $menu_restricted_access_array[$this->current_user_role];
               
                    if ( in_array($id_menu_item, $restricted_access) )
                                        {
                        return true;
                                        }
                                        else
                                        {
                        return false;
                                        }
                }
                else {
                        return true;
                                        }
               
                }
               
     /*
                 *      Element render
                 */
                function start_el(&$output, $item, $depth, $args)
        {
       
            global $wp_query, $menu_restricted_access_array;
            global $g_role,$g_pageid;
            $indent = ( $depth ) ? str_repeat( "\t", $depth ) : '';
                        $g_role=strtolower((trim($item->description)));
                       
                        $str = explode(',',$g_role);
                        for( $i=0; $i< count($str); $i++)
                                {                      
                                       
                                        if (strtolower(trim($str[$i]))==$this->current_user_role)
                                        {                      
                                                $restriction =$item->object_id;        
                                                $menu_restricted_access_array[$this->current_user_role] =array( $restriction);
                                        }
                                       
                                       
                                }
                       
                       
            $class_names = $value = '';
               
            $classes = empty( $item->classes ) ? array() : (array) $item->classes;
            $classes[] = 'menu-item-' . $item->ID;
       
                       
            /*
             *  First test, add custom class to each menu item
             */
                $classes[] = 'my-custom-menu-class';
               
            /*
             *  Detect the menu item matching the unpublished page
             *  Detect the menu item matching the unpublished page
             */
                // -> FLag to display the output
                $item_to_display = true;
                $is_item_published = true;
               
                // -> Gather data of linked object
                $item_data = get_post($item->object_id);
               
                // --> If it's a page, act on the flag
   
                if ( !empty($item_data) && ($item->object == "page") )
                {
                    $is_item_published = ( $item_data->post_status == "publish" ) ? true : false;
                    $item_output = "";
                }
           
            /*
             *  Detect and display by user Role
             **/
                if ( _USE_RESTRICTED_ACCESS )
                {
                    $restrictions_array = $this->getAllRestrictions();
                    $this->isAccessGranted($item->object_id);
                 
                }
                else
                {
                    $item_to_display = $is_item_published;
                }
               
            $class_names = join( ' ', apply_filters( 'nav_menu_css_class', array_filter( $classes ), $item ) );
            $class_names = ' class="' . esc_attr( $class_names ) . '"';
   
       
       
            $id = apply_filters( 'nav_menu_item_id', 'menu-item-'. $item->ID, $item, $args );
            $id = strlen( $id ) ? ' id="' . esc_attr( $id ) . '"' : '';
   
            $output .= $indent . '<li id="menu-item-'. $item->ID . '"' . $value . $class_names .'>';
   
            $attributes  = ! empty( $item->attr_title ) ? ' title="'  . esc_attr( $item->attr_title ) .'"' : '';
            $attributes .= ! empty( $item->target )     ? ' target="' . esc_attr( $item->target     ) .'"' : '';
            $attributes .= ! empty( $item->xfn )        ? ' rel="'    . esc_attr( $item->xfn        ) .'"' : '';
            $attributes .= ! empty( $item->url )        ? ' href="'   . esc_attr( $item->url        ) .'"' : '';
           
                       
               
                        if($depth != 0)
                        {
                    $description = $append = $prepend = "";
                        }
                       
            // --> If the flag is true, when display the output
                               
            if ( $item_to_display )
            {
                $item_output = $args->before;
                $item_output .= '<a'. $attributes .'>';
                $item_output .= $args->link_before .apply_filters( 'the_title', $item->title, $item->ID ).$append; // this is where the strong tags are prepend and append to the description
         
                                $item_output .= '</a>';
                $item_output .= $args->after;
            }
           
            $output .= apply_filters( 'walker_nav_menu_start_el', $item_output, $item, $depth, $args );
        }
}
/*
 *      Restrictions configuration
* 2 is page id of Homepage
 **/
define("_USE_RESTRICTED_ACCESS", true);
$menu_restricted_access_array['subscriber'] = array('2');
 
?>