Ad Notify Sends empty emails

On occasion ad notify sends emails of this form:

Hello xxx,

This is an automatically generated notification about your advertisement "" that is being displayed on the xxxx website.

Your advertisement has been viewed 0 times and clicked 0 times today.
It was viewed 0 times and clicked 1 times yesterday.  It has been viewed 0 times and clicked 3 times since it was activated on never.

You will receive this email every 1 day as long as the ad is active.
You can view additional statistics about this advertisement or update this notification at the following url:
 http://www.example.com/node/

Regards,
xxxx