Email Notifying vendor of new order

Hi,
I'm have a problem modifying the email sent to the vendors when a new order comes in. I have been able to modify emails to the customer and administrator, but not to the vendor. I believe the email is generated by the HTML code at Order Status Notification, because when I change the sender information - it does show up on the email to the vendor. However, when I change any of the html code, I do not see it reflected in the email. It's as though the html is located somewhere else. I'm continuing to look for it, but it's frustrating, so I must be missing something.
Many thanks,
Jim Porter