Better version of the previous patch

Author: marijnh

lib/codemirror.js

@@ -19,7 +19,7 @@ var CodeMirror = (function() {
     var wrapper = targetDocument.createElement("div");
     wrapper.className = "CodeMirror";
     // Work around http://www.quirksmode.org/bugreports/archives/2006/09/Overflow_Hidden_not_hiding.html
-    if (window.ActiveXObject && /MSIE [1-7][\. ]/.test(navigator.userAgent))
+    if (window.ActiveXObject && /MSIE [1-7]\b/.test(navigator.userAgent))
       wrapper.style.position = "relative";
     // This mess creates the base DOM structure for the editor.
     wrapper.innerHTML =