Interesting. This appears to be a Bug in CSS Sculptor. If you select a Rounded Corner layout, and change the footer from normal to any of the other options, then click apply and preview it, you will not be able to set it back to normal.
When you try to set it back to normal, after changing it to any of the other options, the change will not take.
If you do not apply any changes to the footer, the page will be generated correctly though.