diff --git a/xul/content/static.js b/xul/content/static.js
--- a/xul/content/static.js
+++ b/xul/content/static.js
@@ -2413,16 +2413,17 @@ function updateAppMotif(motifURL)
         if (!node)
         {
             node = document.createProcessingInstruction("xml-stylesheet", dataStr);
             document.insertBefore(node, document.firstChild);
         }
         else
         {
             node.data = dataStr;
+            document.insertBefore(node, node.nextSibling);
         }
     }
     catch (ex)
     {
         dd(formatException(ex));
         var err = ex.name;
         // Mozilla 1.0 doesn't like document.insertBefore(...,
         // document.firstChild); though it has a prototype for it -