I had my cart customized for version 3.7.4, after an update to 3.7.7 of this cart, there were some minor changes to the cart and the custom coding isn't working anymore.
I know the exact location of the custom coding for each change and only 3 files edited.
Here are the changes:
1. Session Saving
2. continue shopping function needs to lead back to the previous category page
3. quantity pricing adjustment
4. non www to www redirect