--- a/mobile/chrome/content/Util.js
+++ b/mobile/chrome/content/Util.js
@@ -180,16 +180,17 @@ let Util = {
  * Cache of commonly used elements.
  */
 let Elements = {};
 
 [
   ["browserBundle",      "bundle_browser"],
   ["contentShowing",     "bcast_contentShowing"],
   ["stack",              "stack"],
+  ["panelUI",            "panel-container"],
 ].forEach(function (elementGlobal) {
   let [name, id] = elementGlobal;
   Elements.__defineGetter__(name, function () {
     let element = document.getElementById(id);
     if (!element)
       return null;
     delete Elements[name];
     return Elements[name] = element;

--- a/mobile/chrome/content/browser-ui.js
+++ b/mobile/chrome/content/browser-ui.js
@@ -320,29 +320,31 @@ var BrowserUI = {
       return;
     let panel = this._popup.panel;
     if (panel.hide)
       panel.hide();
   },
   
   _isEventInsidePopup: function _isEventInsidePopup(aEvent) {
     if (!this._popup)
-      return;
+      return false;
     let elements = this._popup.elements;
     let targetNode = aEvent ? aEvent.target : null;
     while (targetNode && elements.indexOf(targetNode) == -1)
       targetNode = targetNode.parentNode;
     return targetNode ? true : false;
   },
 
-  switchPane : function(id) {
+  switchPane : function switchPane(id) {
     let button = document.getElementsByAttribute("linkedpanel", id)[0];
     if (button)
       button.checked = true;
-    document.getElementById("panel-items").selectedPanel = document.getElementById(id);
+
+    let pane = document.getElementById(id);
+    document.getElementById("panel-items").selectedPanel = pane;
   },
 
   get toolbarH() {
     if (!this._toolbarH) {
       let toolbar = document.getElementById("toolbar-main");
       this._toolbarH = toolbar.boxObject.height;
     }
     return this._toolbarH;
@@ -401,20 +403,26 @@ var BrowserUI = {
     browsers.addEventListener("DOMWillOpenModalDialog", this, true);
     
     // listening mousedown for automatically dismiss some popups (e.g. larry)
     window.addEventListener("mousedown", this, true);
 
     // listening escape to dismiss dialog on VK_ESCAPE
     window.addEventListener("keypress", this, true);
 
-    ExtensionsView.init();
-    DownloadsView.init();
-    PreferencesView.init();
-    ConsoleView.init();
+    // Push the panel initialization out of the startup path
+    // (Using a timeout because we have no good way to delay-init [Bug 535366])
+    setTimeout(function() {
+      // We unhide the panelUI so the XBL and settings can initialize
+      Elements.panelUI.hidden = false;
+      ExtensionsView.init();
+      DownloadsView.init();
+      PreferencesView.init();
+      ConsoleView.init();
+    }, 1000);
   },
 
   uninit : function() {
     ExtensionsView.uninit();
     ConsoleView.uninit();
   },
 
   update : function(aState) {
@@ -604,35 +612,36 @@ var BrowserUI = {
 
   isTabsVisible: function isTabsVisible() {
     // The _1, _2 and _3 are to make the js2 emacs mode happy
     let [leftvis,_1,_2,_3] = Browser.computeSidebarVisibility();
     return (leftvis > 0.002);
   },
 
   showPanel: function showPanel(aPage) {
-    let panelUI = document.getElementById("panel-container");
-
-    panelUI.hidden = false;
-    panelUI.width = window.innerWidth;
-    panelUI.height = window.innerHeight;
+    Elements.panelUI.left = 0;
+    Elements.panelUI.hidden = false;
+    Elements.panelUI.width = window.innerWidth;
+    Elements.panelUI.height = window.innerHeight;
 
     Elements.contentShowing.setAttribute("disabled", "true");
 
     if (aPage != undefined)
       this.switchPane(aPage);
   },
 
   hidePanel: function hidePanel() {
-    let panelUI = document.getElementById("panel-container");
-    panelUI.hidden = true;
-
+    Elements.panelUI.hidden = true;
     Elements.contentShowing.removeAttribute("disabled");
   },
-  
+
+  isPanelVisible: function isPanelVisible() {
+    return (!Elements.panelUI.hidden && Elements.panelUI.left == 0);
+  },
+
   switchTask: function switchTask() {
     try {
       let phone = Cc["@mozilla.org/phone/support;1"].createInstance(Ci.nsIPhoneSupport);
       phone.switchTask();
     } catch(e) { }
   },
   
 #ifdef WINCE
@@ -809,21 +818,20 @@ var BrowserUI = {
         button.disabled = true;
         setTimeout(function() { button.disabled = false; }, 5000);
 
         Sanitizer.sanitize();
         break;
       }
       case "cmd_panel":
       {
-        let panelUI = document.getElementById("panel-container");
-        if (panelUI.hidden)
+        if (BrowserUI.isPanelVisible())
+          this.hidePanel();
+        else
           this.showPanel();
-        else
-          this.hidePanel();
         break;
       }
       case "cmd_zoomin":
         Browser.zoom(-1);
         break;
       case "cmd_zoomout":
         Browser.zoom(1);
         break;

--- a/mobile/chrome/content/browser.js
+++ b/mobile/chrome/content/browser.js
@@ -540,18 +540,18 @@ var Browser = {
     this.addTab(whereURI, true);
     if (whereURI == "about:blank") {
       BrowserUI.showToolbar(true);
       BrowserUI.showAutoComplete();
     }
 
     // JavaScript Error Console
     if (gPrefService.getBoolPref("browser.console.showInPanel")){
-      let tool_console = document.getElementById("tool-console");
-      tool_console.hidden = false;
+      let button = document.getElementById("tool-console");
+      button.hidden = false;
     }
 
     bv.commitBatchOperation();
 
     // If some add-ons were disabled during during an application update, alert user
     if (gPrefService.prefHasUserValue("extensions.disabledAddons")) {
       let addons = gPrefService.getCharPref("extensions.disabledAddons").split(",");
       if (addons.length > 0) {

--- a/mobile/chrome/content/browser.xul
+++ b/mobile/chrome/content/browser.xul
@@ -326,17 +326,17 @@
       <hbox id="bookmark-form" align="start">
         <image id="bookmark-image"/>
       </hbox>
       <hbox pack="center">
         <button class="button-dark" label="&editBookmarkDone.label;" oncommand="BookmarkHelper.save();"/>
       </hbox>
     </vbox>
 
-    <box id="panel-container" hidden="true" class="panel-dark">
+    <box id="panel-container" class="panel-dark" style="-moz-stack-sizing: ignore" left="10000" hidden="true">
       <box id="panel-controls" oncommand="BrowserUI.switchPane(event.target.getAttribute('linkedpanel'));">
         <toolbarbutton id="tool-panel-close" class="page-button button-image" command="cmd_panel"/>
         <toolbarbutton id="tool-addons" type="radio" group="1" class="panel-button button-image" linkedpanel="addons-container"/>
         <toolbarbutton id="tool-downloads" type="radio" group="1" class="panel-button button-image" linkedpanel="downloads-container"/>
         <toolbarbutton id="tool-preferences" type="radio" group="1" checked="true" class="panel-button button-image" linkedpanel="prefs-container"/>
         <toolbarbutton id="tool-console" type="radio" group="1" hidden="true" class="panel-button button-image" linkedpanel="console-container"/>
       </box>
       <deck id="panel-items" selectedIndex="2" flex="1">

--- a/mobile/chrome/content/downloads.js
+++ b/mobile/chrome/content/downloads.js
@@ -113,19 +113,18 @@ var DownloadsView = {
     if (this._list.itemCount == 0) {
       let emptyString = Elements.browserBundle.getString("downloadsEmpty");
       let emptyItem = this._list.appendItem(emptyString);
       emptyItem.id = "dl-empty-message";
     }
   },
 
   get visible() {
-    let panel = document.getElementById("panel-container");
     let items = document.getElementById("panel-items");
-    if (panel.hidden == false && items.selectedPanel.id == "downloads-container")
+    if (BrowserUI.isPanelVisible() && items.selectedPanel.id == "downloads-container")
       return true;
     return false;
   },
 
   init: function dv_init() {
     if (this._initialized)
       return;
     this._initialized = true;

--- a/mobile/chrome/content/extensions.js
+++ b/mobile/chrome/content/extensions.js
@@ -207,19 +207,18 @@ var ExtensionsView = {
       let item = items[i];
       if (item.hideOptions)
         item.hideOptions();
     }
     this._list.ensureSelectedElementIsVisible();
   },
 
   get visible() {
-    let panel = document.getElementById("panel-container");
     let items = document.getElementById("panel-items");
-    if (panel.hidden == false && items.selectedPanel.id == "addons-container")
+    if (BrowserUI.isPanelVisible() && items.selectedPanel.id == "addons-container")
       return true;
     return false;
   },
 
   init: function ev_init() {
     if (this._extmgr)
       return;