What where the settings you used when adding the display to the checkout page?
on the second step of the display manager, you can set elements to show for the desktop, tablet layout or phone layout. The price under the product name should be set to show for tablets and lower, and the price column should be set to display for desktop only. that is how it is set on the cart page:
<p id="bbCart_JSON_Display_Price_13904977256301" class="eC_ItemPrice max_tablet">$80.00</p>
on the checkout page, it is missing the max tablet class:
<p id="bbCart_JSON_Display_Price_13904977256301" class="eC_ItemPrice">$80.00</p>
remove the display manager from the checkout page and reapply it, make note of the settings you use on the second step.