Adjusting width of "shopping cart" widget (marketplace)

Hello,

I am trying to use MarketPlace with the theme 'blogs mu'; however, I am running into an overlap issue where when my 'shopping cart' widget is populated with a product, it overlaps the product page content: Please see here: http://dallassmithcorp.com/wp-content/uploads/overlap.png

Any guidance on how to control the width, or stop this overlap from happening, is greatly appreciated.

Thanks

J