It is one of the postbit templates, can't remember which one off the top of my head. postbitnew possibly, have a look through them and see if you can tell which it is.
To find the template to modify, do this - vboptions > General Settings > Add Template Name in HTML Comments > set to Yes . Then go back to your page and view the source code and you will see the name of the template called around your part of the code.