we had the same issue on website. It started to happen from yesterday 04/07/2013. It only happens in IE7 browser. We just omitted the browser from showing the Like box with below code.
if (navigator.appVersion.indexOf("MSIE 7.") == -1) {
var js, fjs = d.getElementsByTagName(s)[0];
if (d.getElementById(id)) return;
js = d.createElement(s); js.id = id;
js.src = "//connect.facebook.net/en_US/all.js#xfbml=1";
fjs.parentNode.insertBefore(js, fjs);
}