You´re loading all theme css files in the wp-admin section. This causes problems when you´re using the same class names as WordPress.
For example, WordPress uses the
.clear declaration only to clear floats, while you also set the width and height of the element to 0. This makes all elements in wp-admin using the
.clear class disappear.
Some of my plugin setting forms were invisible because of your stylesheet.
I solved it by loading the theme stylesheets only in the frontend, not int he admin section.