see: http://code.google.com/p/shellinabox/issues/detail?id=202#c20
From ea7fea87a2cdba9df40f27464ce27f5d192ac389 Mon Sep 17 00:00:00 2001
From: Alexander Sulfrian <alexander.sulfrian@fu-berlin.de>
Date: Mon, 7 Jan 2013 19:11:49 +0100
Subject: [PATCH 1/2] add new keyCodes used by >=FF15
--- shellinabox/vt100.jspp
+++ shellinabox/vt100.jspp
@@ -2894,10 +2894,10 @@
     event.keyCode == 226;
   var normalKey                 =
     alphNumKey                                   ||
-    event.keyCode ==  59 || event.keyCode ==  61 ||
+    event.keyCode >=  59 && event.keyCode <=  64 ||
     event.keyCode == 106 || event.keyCode == 107 ||
     event.keyCode >= 109 && event.keyCode <= 111 ||
-    event.keyCode >= 186 && event.keyCode <= 192 ||
+    event.keyCode >= 160 && event.keyCode <= 192 ||
     event.keyCode >= 219 && event.keyCode <= 223 ||
     event.keyCode == 252;
   try {