You've some sort of JS on the page that is not compatible with IE. That JS is causing a Fatal Error, which is preventing our JS curvy from functioning. Please try changing to default Joomla template and see if issue persists. If so please try disabling Joomla/CB plugins 1 by 1 until resolved. If still present please check modules. As for rounded corners we did not develop your template nor does it seam CB related, please contact the author of your template.