diff --git a/toolkit/mozapps/extensions/AddonLogging.jsm b/toolkit/mozapps/extensions/AddonLogging.jsm
index 453b6575d12f..362439bae23a 100644
--- a/toolkit/mozapps/extensions/AddonLogging.jsm
+++ b/toolkit/mozapps/extensions/AddonLogging.jsm
@@ -92,8 +92,8 @@ AddonLogger.prototype = {
                         Ci.nsIScriptError.errorFlag, "component javascript");
     Services.console.logMessage(consoleMessage);
 
-    if (gDebugLogEnabled)
-      dump("*** " + message + "\n");
+    // Always dump errors, in case the Console Service isn't listening yet
+    dump("*** " + message + "\n");
 
     try {
       var tstamp = new Date();
diff --git a/toolkit/mozapps/extensions/DeferredSave.jsm b/toolkit/mozapps/extensions/DeferredSave.jsm
index 298a4f3a5609..34d7aa8a67f8 100644
--- a/toolkit/mozapps/extensions/DeferredSave.jsm
+++ b/toolkit/mozapps/extensions/DeferredSave.jsm
@@ -38,7 +38,7 @@ const DEFAULT_SAVE_DELAY_MS = 50;
  *        that marks the data as needing to be saved, and when the DeferredSave
  *        begins writing the data to disk. Default 50 milliseconds.
  */
-function DeferredSave(aPath, aDataProvider, aDelay) {
+this.DeferredSave = function (aPath, aDataProvider, aDelay) {
   // Set up loggers for this instance of DeferredSave
   let leafName = OS.Path.basename(aPath);
   Cu.import("resource://gre/modules/AddonLogging.jsm");
@@ -87,7 +87,7 @@ function DeferredSave(aPath, aDataProvider, aDelay) {
     this._delay = DEFAULT_SAVE_DELAY_MS;
 }
 
-DeferredSave.prototype = {
+this.DeferredSave.prototype = {
   get dirty() {
     return this._pending || this.writeInProgress;
   },
diff --git a/toolkit/mozapps/extensions/XPIProvider.jsm b/toolkit/mozapps/extensions/XPIProvider.jsm
index 98cbeef518f8..9a54cc92df3e 100644
--- a/toolkit/mozapps/extensions/XPIProvider.jsm
+++ b/toolkit/mozapps/extensions/XPIProvider.jsm
@@ -192,9 +192,10 @@ var gLazyObjectsLoaded = false;
 
 function loadLazyObjects() {
   let scope = {};
+  scope.AddonInternal = AddonInternal;
+  scope.XPIProvider = XPIProvider;
   Services.scriptloader.loadSubScript("resource://gre/modules/XPIProviderUtils.js",
                                       scope);
-  scope.XPIProvider = XPIProvider;
 
   for (let name of LAZY_OBJECTS) {
     delete gGlobalScope[name];
@@ -2803,8 +2804,10 @@ var XPIProvider = {
           newAddon = loadManifestFromFile(file);
         }
         // The add-on in the manifest should match the add-on ID.
-        if (newAddon.id != aId)
-          throw new Error("Incorrect id in install manifest");
+        if (newAddon.id != aId) {
+          throw new Error("Invalid addon ID: expected addon ID " + aId +
+                          ", found " + newAddon.id + " in manifest");
+        }
       }
       catch (e) {
         WARN("Add-on is invalid", e);
@@ -4246,7 +4249,6 @@ var XPIProvider = {
   }
 };
 
-
 function getHashStringForCrypto(aCrypto) {
   // return the two-digit hexadecimal code for a byte
   function toHexString(charCode)
diff --git a/toolkit/mozapps/extensions/XPIProviderUtils.js b/toolkit/mozapps/extensions/XPIProviderUtils.js
index ad36119d54bd..0e442eaaa136 100644
--- a/toolkit/mozapps/extensions/XPIProviderUtils.js
+++ b/toolkit/mozapps/extensions/XPIProviderUtils.js
@@ -12,6 +12,8 @@ const Cu = Components.utils;
 Cu.import("resource://gre/modules/XPCOMUtils.jsm");
 Cu.import("resource://gre/modules/Services.jsm");
 
+XPCOMUtils.defineLazyModuleGetter(this, "AddonManager",
+                                  "resource://gre/modules/AddonManager.jsm");
 XPCOMUtils.defineLazyModuleGetter(this, "AddonRepository",
                                   "resource://gre/modules/AddonRepository.jsm");
 XPCOMUtils.defineLazyModuleGetter(this, "FileUtils",