diff --git a/docshell/base/nsDocShell.cpp b/docshell/base/nsDocShell.cpp
index 501949660629..b718aa861fe2 100644
--- a/docshell/base/nsDocShell.cpp
+++ b/docshell/base/nsDocShell.cpp
@@ -7467,8 +7467,9 @@ nsDocShell::CheckClassifier(nsIChannel *aChannel)
 
     classifier->SetChannel(aChannel);
     nsresult rv = classifier->Run();
-    if (rv == NS_ERROR_FACTORY_NOT_REGISTERED) {
-        // no URI classifier, ignore this
+    if (rv == NS_ERROR_FACTORY_NOT_REGISTERED ||
+        rv == NS_ERROR_NOT_AVAILABLE) {
+        // no URI classifier => ignored cases
         return NS_OK;
     }
     NS_ENSURE_SUCCESS(rv, rv);
diff --git a/toolkit/components/build/nsToolkitCompsModule.cpp b/toolkit/components/build/nsToolkitCompsModule.cpp
index 4da2431a38d9..e561d8303877 100644
--- a/toolkit/components/build/nsToolkitCompsModule.cpp
+++ b/toolkit/components/build/nsToolkitCompsModule.cpp
@@ -86,10 +86,27 @@ NS_GENERIC_FACTORY_CONSTRUCTOR(nsDownloadProxy)
 NS_GENERIC_FACTORY_CONSTRUCTOR(nsTypeAheadFind)
 
 #ifdef MOZ_URL_CLASSIFIER
-NS_GENERIC_FACTORY_SINGLETON_CONSTRUCTOR(nsUrlClassifierDBService,
-                                         nsUrlClassifierDBService::GetInstance)
 NS_GENERIC_FACTORY_CONSTRUCTOR(nsUrlClassifierStreamUpdater)
 NS_GENERIC_FACTORY_CONSTRUCTOR_INIT(nsUrlClassifierUtils, Init)
+
+static NS_IMETHODIMP
+nsUrlClassifierDBServiceConstructor(nsISupports *aOuter, REFNSIID aIID,
+                                    void **aResult)
+{
+    nsresult rv;
+    NS_ENSURE_ARG_POINTER(aResult);
+    NS_ENSURE_NO_AGGREGATION(aOuter);
+
+    nsUrlClassifierDBService *inst = nsUrlClassifierDBService::GetInstance(&rv);
+    if (NULL == inst) {
+        return rv;
+    }
+    /* NS_ADDREF(inst); */
+    rv = inst->QueryInterface(aIID, aResult);
+    NS_RELEASE(inst);
+
+    return rv;
+}
 #endif
 
 #ifdef MOZ_FEEDS
diff --git a/toolkit/components/url-classifier/src/nsUrlClassifierDBService.cpp b/toolkit/components/url-classifier/src/nsUrlClassifierDBService.cpp
index 8b2e55d39b53..5f6db37f8452 100644
--- a/toolkit/components/url-classifier/src/nsUrlClassifierDBService.cpp
+++ b/toolkit/components/url-classifier/src/nsUrlClassifierDBService.cpp
@@ -650,7 +650,13 @@ nsUrlClassifierDBServiceWorker::Init()
   // portable between machine types, so store it in the local profile dir.
   nsresult rv = NS_GetSpecialDirectory(NS_APP_USER_PROFILE_LOCAL_50_DIR,
                                        getter_AddRefs(mDBFile));
-  if (NS_FAILED(rv)) return rv;
+
+  if (NS_FAILED(rv)) {
+    rv = NS_GetSpecialDirectory(NS_APP_USER_PROFILE_50_DIR,
+                                getter_AddRefs(mDBFile));
+  }
+
+  if (NS_FAILED(rv)) return NS_ERROR_NOT_AVAILABLE;
 
   rv = mDBFile->Append(NS_LITERAL_STRING(DATABASE_FILENAME));
   NS_ENSURE_SUCCESS(rv, rv);
@@ -2266,16 +2272,20 @@ NS_IMPL_THREADSAFE_ISUPPORTS3(nsUrlClassifierDBService,
                               nsIObserver)
 
 /* static */ nsUrlClassifierDBService*
-nsUrlClassifierDBService::GetInstance()
+nsUrlClassifierDBService::GetInstance(nsresult *result)
 {
+  *result = NS_OK;
   if (!sUrlClassifierDBService) {
     sUrlClassifierDBService = new nsUrlClassifierDBService();
-    if (!sUrlClassifierDBService)
+    if (!sUrlClassifierDBService) {
+      *result = NS_ERROR_OUT_OF_MEMORY;
       return nsnull;
+    }
 
     NS_ADDREF(sUrlClassifierDBService);   // addref the global
 
-    if (NS_FAILED(sUrlClassifierDBService->Init())) {
+    *result = sUrlClassifierDBService->Init();
+    if (NS_FAILED(*result)) {
       NS_RELEASE(sUrlClassifierDBService);
       return nsnull;
     }
diff --git a/toolkit/components/url-classifier/src/nsUrlClassifierDBService.h b/toolkit/components/url-classifier/src/nsUrlClassifierDBService.h
index 6f47ef9e7aa4..7c922bec99ce 100644
--- a/toolkit/components/url-classifier/src/nsUrlClassifierDBService.h
+++ b/toolkit/components/url-classifier/src/nsUrlClassifierDBService.h
@@ -61,7 +61,7 @@ public:
 
   nsresult Init();
 
-  static nsUrlClassifierDBService* GetInstance();
+  static nsUrlClassifierDBService* GetInstance(nsresult *result);
 
 #ifdef MOZILLA_1_8_BRANCH
   NS_DEFINE_STATIC_IID_ACCESSOR(NS_URLCLASSIFIERDBSERVICE_CID)