Problems with "Edit Page" Page

Hi to all, i would like no know how to fix this problem i have with the edit page interface, (screenshot: http://imm.io/Eoxd) it looks like a deface, i thing it might be cause from the theme, cause when i use any other theme it works perfectly, and the main reason i need to fix this is because i cant use “wordpress SEO by yoast” from the edit page at least i change the theme, please any idea? thank you.