[Michael P]

Well, since you are getting the emails it means the script is running. But, you can also see how the query isn't taking for some reason.

Under line 72ish in sendnotice.php:

$query = "UPDATE {$Globals['pp_db_prefix']}products SET status='$today',enddate='$newend' WHERE id=$id";

add:

print $query;

and then run the sendnotice.php script in your browser to see the output.