Triggering NOTIFY new content emails

I have Notify set to weekly, and our host's Cpanel set up to run cron.php every night. The log records say that cron is running properly at night.

The cpanel triggered cron doesn't seem to send notify emails.

When I run cron.php manually from my browser, it does trigger the notify emails.

Is there any reason why running cron through cpanel wouldn't trigger the notify function? I use the command wget -O - -q -t 1 http://sitename/cron.php

Thanks
Michael