Why is wp-cron taking up so many resources?

From /var/logs/httpd/error-log:

[Thu Apr 22 01:41:15 2010] [notice] mod_fcgid: call /var/www/vhosts/mydomain.com/httpdocs/wp-cron.php with wrapper /usr/bin/php-cgi  
[Thu Apr 22 01:41:15 2010] [notice] mod_fcgid: server /var/www/vhosts/mydomain.com/httpdocs/wp-cron.php(17999) started  
...The previous line shows up 8661 times...

What's in Cron?

Apr 22, 2010 @ 18:25 (1271960731)    Twice Daily    wp_version_check  
Apr 22, 2010 @ 18:25 (1271960731)    Twice Daily    wp_update_plugins  
Apr 22, 2010 @ 18:25 (1271960731)    Twice Daily    wp_update_themes  
Apr 23, 2010 @ 12:21 (1272025294)    Once Daily wp_scheduled_delete  

Running CentoOS 5/plesk 9.3/php as FastCGI/suExec with WP 2.9.2

Thanks in advance.

From serverfault Gaia

• is the request to wp-cron.php coming from the local host, or somewhere else? if the former, it looks like WordPress’s timing is doing something wrong (see spawn_cron() in wp-includes/cron.php), if the latter — disable access to it via .htaccess or similar.

  Gaia : it is coming from the local host. i guess the next step is find out the sql script to add the commentmeta table and see if the problem goes away. thanks
  From Mo