Opening a page with few iframes wtih IE10 while developer tools are open breaks the styles in those iframes.
Here are couple iframes showing The Verge
Now open this page with IE10, switch developer tools on and reload the page. Notice how The Verge is missing its stylsheets.
Follow this bug here https://connect.microsoft.com/IE/feedback/details/796740/developer-tools-in-ie10-break-styles-in-iframes