The only thing we did when this happened was I was adding in the email address for the shipping replies, payment replies, that was all. Nothing else was done or changed on any of the code. It was all being done through the online Admin login.
Also, what I did try was to reupload the corrupt pages as I noticed the file sizes were different on the site than what they were on my local drive where I stored the original files.
As I am newer to this whole area of PHP, I am not familiar or understanding how you would like me to go about making changes to these items. for the db, I am not sure where that is located. We are using 1&1 as our host.