diff --git a/dom/tests/mochitest/ajax/offline/Makefile.in b/dom/tests/mochitest/ajax/offline/Makefile.in
index d22e26cf0a6..8e944a3e2e5 100644
--- a/dom/tests/mochitest/ajax/offline/Makefile.in
+++ b/dom/tests/mochitest/ajax/offline/Makefile.in
@@ -59,9 +59,11 @@ _TEST_FILES	= \
 	test_changingManifest.html \
 	test_refetchManifest.html \
 	test_offlineIFrame.html \
+	test_offlineMode.html \
 	test_bug445544.html \
 	test_foreign.html \
 	test_fallback.html \
+	test_updatingManifest.html \
 	445544_part1.html \
 	445544_part2.html \
 	445544.cacheManifest \
@@ -87,6 +89,9 @@ _TEST_FILES	= \
 	foreign2.cacheManifest \
 	foreign2.cacheManifest^headers^ \
 	foreign2.html \
+	notonwhitelist.html \
+	onwhitelist.html \
+	onwhitelist.html^headers^ \
 	updatingIFrame.html \
 	updatingIFrame.html^headers^ \
 	updatingImplicit.html \
@@ -104,12 +109,5 @@ _TEST_FILES	= \
 	offlineChild.html \
 	$(NULL)
 
-# Bug 466314 - updatingImplicit.html (used by test_offlineMode.html and test_updatingManifest.html) crashes SeaMonkey
-#	test_offlineMode.html \
-#	notonwhitelist.html \
-#	test_updatingManifest.html \
-#	onwhitelist.html \
-#	onwhitelist.html^headers^ \
-
 libs::	$(_TEST_FILES)
 	$(INSTALL) $(foreach f,$^,"$f") $(DEPTH)/_tests/testing/mochitest/tests/$(relativesrcdir)
diff --git a/uriloader/prefetch/nsOfflineCacheUpdate.cpp b/uriloader/prefetch/nsOfflineCacheUpdate.cpp
index 3936b51328a..88c03e76844 100644
--- a/uriloader/prefetch/nsOfflineCacheUpdate.cpp
+++ b/uriloader/prefetch/nsOfflineCacheUpdate.cpp
@@ -67,6 +67,7 @@
 #include "nsServiceManagerUtils.h"
 #include "nsStreamUtils.h"
 #include "nsThreadUtils.h"
+#include "nsProxyRelease.h"
 #include "prlog.h"
 
 static nsOfflineCacheUpdateService *gOfflineCacheUpdateService = nsnull;
@@ -1828,6 +1829,13 @@ nsOfflineCacheUpdate::Finish()
 {
     LOG(("nsOfflineCacheUpdate::Finish [%p]", this));
 
+    // Because call to service->UpdateFinished(this) at the end of this method
+    // may relese the last reference to this object but we still want to work
+    // with it after Finish() call ended, make sure to release this instance in
+    // the next thread loop round.
+    NS_ADDREF_THIS();
+    NS_ProxyRelease(NS_GetCurrentThread(), this, PR_TRUE);
+
     mState = STATE_FINISHED;
 
     nsOfflineCacheUpdateService* service =