Marketpress shopping cart getting jumbled

Ok so I installed marketpress on a wordpress site using the theme Clean Home. I have the plugin working perfectly for me and most people. However, some customers call in saying the shopping cart page is jumbled and crazy looking. I cannot for the life of me replicate this problem.

Does anyone know what could be causing this for people? What might affect the styling of the pages? I would love to have an answer for them to fix it and not have to take orders over the phone. Any help appreciated.