refer to post #8. Classic is still largely table based where the template_default is more css based.
Unfortunately, the system implies that Classic is the way to go by stating "Wherever you see a folder named "classic" you can safely add your own /CUSTOM folder."
BUT...
The directions for creating the CUSTOM template include "Next, copy the includes/templates/template_default/css directory and place the folder and its files in your new includes/templates/CUSTOM/ folder."

There's also a very good chart in the downloads section that shows the correct positioning of custom directories. It gets overlooked often because it says it's for 1.3.6 but, it's current for 1.3.8a as well. http://www.zen-cart.com/index.php?ma...roducts_id=298

Best to get things in order from the beginning. That way, future upgrades will be a breeze.