Order info in the db

I have a problem with the information which is being saved in the database.

I am unable to find any solution and what I would appreciate is some information, if someone can provide it (it will be very difficult to provide a solution, because I do not even know what is going on).

When a customer places an order, Zencart triggers the email with the order and saves the data in the db.

The email sent to the client is always correct; we have not detected any mistake and the amounts are correctly calculated. The information to process payment (Paypal / Credit card), is also correct (I am referring to the order total).

However the information stored in the db with respect to the order is not always correct and sometimes it is stored without VAT.

It is not happening in any specific combination of shipping and payment method; it happens sometimes in cod, sometimes in Paypal and also sometimes in storepickup, in flat shipping... so it is not that. (Only affecting the info included in the db).

My question is:

Can someone tell me the files that deal with the email which is sent to the clients and the file storing the order info in the db, so I can check them?

Thanks in advance for your help
(and sorry if it is a very easy question, I am not an expert and have been unable to find such files).

Moving this out of the Bug Reports section, because it's not a bug in Zen Cart core code.

1. MOST IMPORTANT ISSUE: You're using an obsolete version of Zen Cart with known security holes. You need to upgrade ASAP.

2. The emails are sent AFTER the order details are stored in the database, and are built using the same variables/data. The only reason they'd be different is if your code has been altered from its original design. It's largely all handled in /includes/classes/order.php. But since you allege it's not working correctly for you, it's possible that you've got various other pieces that have been altered incorrectly as well.

I recommend following these steps: http://www.zen-cart.com/wiki/index.php/Recovering_From_Hacks ... until you've completely proven that nothing is compromised and that nothing extra has been added that doesn't belong and that all your database data is perfectly intact.

I wrote too fast...

Great!! that is somewhere to start!!!
Thanks a lot!