cron wp_schedule_event

I can’t get wordpress’ cronjob work:

Here what I have done:

<?php

function hlex_install() {
	wp_schedule_event(time(), 'hourly', 'hlex_timing_job');
}

function hlex_cronjob() {
    die('cronjob');
}

function hlex_deactivation() {
	wp_clear_scheduled_hook('hlex_timing_job');
}

register_activation_hook(__FILE__, 'hlex_install');

register_deactivation_hook(__FILE__, 'hlex_deactivation');

add_action('hlex_timing_job', 'hlex_cronjob');
?>

The wp_schedule_event works cause I can see in the table wp_options (option_name=’cron’ ) something like: i:1270343829;a:1:{s:15:”hlex_timing_job”;

wp_clear_scheduled_hook works too because if I deactivate the plugin “hlex_timing_job” has gone from the “cron” row of the wp_options table.

The problem is that hlex_cronjob() is never executed or at least I’ve never seen the word ‘cronjob’ printed.

I hope someone can help me.

Thanks