Need to change download button ID since old 3.6 extension hides it, so someone in FF4 with old 3.6 extension was not seeing the download button.

dev/index.html

@@ -65,7 +65,7 @@
       <div class="c2 logo">
       </div>
       <div class="c1 dl">
-        <button id="download" class="download downloadXpi">
+        <button id="downloadFF4" class="download downloadXpi">
           install F1
           <span class="meta">available for Firefox 4 beta</span>
         </button>

dev/index.js

@@ -46,7 +46,7 @@ function (require,   $,        hashDispatch) {
 
         //Do not show install button for unsupported browsers.
         if (!supported) {
-            $('#download').hide();
+            $('#downloadFF4').hide();
             $('#no36').show();
             $('#info36').show();
             $('#firefox').show();