Well, this is a tough one, at least for me. A quick fix would be to turn the right side column off when you go to the shopping cart.
Do this in the includes/templates/cherry_zen/common/tpl_main.page.php
Look for:
Code:
// the following IF statement can be duplicated/modified as needed to set additional flags
if (in_array($current_page_base,explode(",",'account_history_info,login,shopping_cart,checkout_payment,checkout_confirmation,tracker,no_account,list_pages_to_skip_all_right_sideboxes_on_here,separated_by_commas,and_no_spaces')) ) {
$flag_disable_left = true;
add the code in red to that line and when they go to the shopping cart, it will shut off the left column and come back on if they continue to shop.
I would need to see your php files in order for me to fix it. It has to be something wrong in one of your php files, but which one, I do not know as I am unable to duplicate it here, but I have verified your css is fine.
JT
}