diff --git a/dom/contacts/ContactManager.js b/dom/contacts/ContactManager.js
index cd7efd9938a..cb96e0ca76e 100644
--- a/dom/contacts/ContactManager.js
+++ b/dom/contacts/ContactManager.js
@@ -334,8 +334,6 @@ ContactManager.prototype = {
                      "Contact:Save:Return:OK", "Contact:Save:Return:KO",
                      "Contact:Remove:Return:OK", "Contact:Remove:Return:KO"]);
 
-    Services.obs.addObserver(this, "inner-window-destroyed", false);
-
     let principal = aWindow.document.nodePrincipal;
     let secMan = Cc["@mozilla.org/scriptsecuritymanager;1"].getService(Ci.nsIScriptSecurityManager);
 
diff --git a/dom/contacts/fallback/ContactDB.jsm b/dom/contacts/fallback/ContactDB.jsm
index 5652e9c68f9..9be7d3afc81 100644
--- a/dom/contacts/fallback/ContactDB.jsm
+++ b/dom/contacts/fallback/ContactDB.jsm
@@ -153,27 +153,10 @@ ContactDB.prototype = {
       };
 
       txn.onabort = function (event) {
-        debug("Caught error on transaction" + event.target.error.name);
-        switch(event.target.error.name) {
-          case "AbortError":
-          case "ConstraintError":
-          case "DataError":
-          case "SyntaxError":
-          case "InvalidStateError":
-          case "NotFoundError":
-          case "QuotaExceededError":
-          case "ReadOnlyError":
-          case "TimeoutError":
-          case "TransactionInactiveError":
-          case "VersionError":
-          case "UnknownError":
-            failureCb("UnknownError");
-            break;
-          default:
-            debug("Unknown error", event.target.error.name);
-            failureCb("UnknownError");
-            break;
-        }
+        debug("Caught error on transaction");
+        // FIXXMEE: this will work in the future. Bug 748630
+        // failureCb(event.target.error.name);
+        failureCb("UnknownError");
       };
       callback(txn, store);
     }, failureCb);
diff --git a/dom/contacts/fallback/ContactService.jsm b/dom/contacts/fallback/ContactService.jsm
index 5eb2b6c6821..381f864c112 100644
--- a/dom/contacts/fallback/ContactService.jsm
+++ b/dom/contacts/fallback/ContactService.jsm
@@ -61,6 +61,7 @@ let DOMContactManager = {
     this._messages = null;
     if (this._db)
       this._db.close();
+    this._db = null;
   },
 
   receiveMessage: function(aMessage) {