static/tinymce/tiny_mce_src.js
function(find, replace, str) {
			// On IE9 we have to fake $x replacement
			if (isRegExpBroken) {
				return str.replace(find, function() {
					var val = replace, args = arguments, i;

					for (i = 0; i < args.length - 2; i++) {
						if (args[i] === undef) {
							val = val.replace(new RegExp('\\$' + i, 'g'), '');
						} else {
							val = val.replace(new RegExp('\\$' + i, 'g'), args[i]);
						}
					}

					return val;
				});
			}

			return str.replace(find, replace);
		}
function(find, replace, str) {
			// On IE9 we have to fake $x replacement
			if (isRegExpBroken) {
				return str.replace(find, function() {
					var val = replace, args = arguments, i;

					for (i = 0; i < args.length - 2; i++) {
						if (args[i] === undef) {
							val = val.replace(new RegExp('\\$' + i, 'g'), '');
						} else {
							val = val.replace(new RegExp('\\$' + i, 'g'), args[i]);
						}
					}

					return val;
				});
			}

			return str.replace(find, replace);
		}
Fix function for IE 9 where regexps isn't working correctly Todo: remove me once MS fixes the bug