mysql select with sum problem

Hi there,
I have these two tables
CREATE TABLE IF NOT EXISTS `coocoo_items` (
  `id` int(8) NOT NULL auto_increment,
  `title` varchar(40) collate utf8_unicode_ci NOT NULL,
  `date` timestamp NOT NULL default CURRENT_TIMESTAMP on update CURRENT_TIMESTAMP,
  `category` int(8) NOT NULL,
  `description` text collate utf8_unicode_ci NOT NULL,
  `image` varchar(50) collate utf8_unicode_ci NOT NULL,
  `cost` float NOT NULL,
  `rented_to` int(8) NOT NULL,
  `num` int(11) NOT NULL,
  PRIMARY KEY  (`id`)
) ENGINE=MyISAM  DEFAULT CHARSET=utf8 COLLATE=utf8_unicode_ci AUTO_INCREMENT=28 ;


CREATE TABLE IF NOT EXISTS `rental_events` (
  `id` int(11) NOT NULL auto_increment,
  `item_id` int(11) NOT NULL,
  `form_id` int(11) NOT NULL,
  `art_id` int(11) NOT NULL,
  `prod_id` int(11) NOT NULL,
  `date_rented` timestamp NOT NULL default CURRENT_TIMESTAMP,
  `income` float NOT NULL,
  PRIMARY KEY  (`id`)
) ENGINE=MyISAM  DEFAULT CHARSET=latin1 AUTO_INCREMENT=5 ;

The first one has the items and the second one some events concerning those items.
I wanted to get all the properties of the items, and for each item to get how many times it appears on the rental_events table as well as the summary of the income field.

This is my sql
$sql = "SELECT
            ".TBL_ITEMS.".id,
            title,
            category,
            image,
            num,
            cost,
            rented_to,
            COUNT(rental_events.id) as cnt,
            SUM(income) as inc
            FROM " .TBL_ITEMS. " , rental_events
            WHERE ".TBL_ITEMS.".id=rental_events.item_id
            GROUP BY " . TBL_ITEMS.".id
            ORDER BY " . $orderby . " " . $asc_desc;
and it shows only the items that appear on the rental_events table. Reasonable but i can't figure out how to show all (with zeros for cnt and inc) with one query.

Any ideas from the SQL experts?