When I use one of the TelerikMetro themes (the default green one of the blue one) and show a Yes/No message box, the close button is not drawn correctly. Because it's a yes/no message, the close button is disabled and is drawn with a gray background. But the gray background ends up going outside of the button and looks really weird. I can reproduce this in the demos included in the Q1 2015 SP1 release. See the attached screenshots for an example.