I think you have a lot of text on the homepage that could be used for product images. It's not instantly clear (at a glance) what you do, or that there are products for sale.
You should put some product images on the main page that link to the pages in your shopping cart where you can but them.
To make it more seamless, you might want to remove some of the outside borders in the cubecart pages and maybe remove the third column on the right and move those elements (shopping cart, popular products, newsletter, free shipping, etc) to the left hand column.
The blue borders around the boxes could be changed to one of the existing colors in the site layout as well.