diff --git a/services/sync/modules/resource.js b/services/sync/modules/resource.js
index e85990e1bfb..3850edc308b 100644
--- a/services/sync/modules/resource.js
+++ b/services/sync/modules/resource.js
@@ -149,7 +149,8 @@ Resource.prototype = {
       getService(Ci.nsIIOService);
     this._lastChannel = ios.newChannel(this.spec, null, null).
       QueryInterface(Ci.nsIHttpChannel);
-
+    this._lastChannel.notificationCallbacks = new badCertListener();
+    
     let headers = this.headers; // avoid calling the authorizer more than once
     for (let key in headers) {
       if (key == 'Authorization')
@@ -348,3 +349,30 @@ JsonFilter.prototype = {
     self.done(this._json.decode(data));
   }
 };
+
+function badCertListener() {
+}
+badCertListener.prototype = {
+  getInterface: function(aIID) {
+    return this.QueryInterface(aIID);
+  },
+  
+  QueryInterface: function(aIID) {
+    if (aIID.equals(Components.interfaces.nsIBadCertListener2) ||
+        aIID.equals(Components.interfaces.nsIInterfaceRequestor) ||
+        aIID.equals(Components.interfaces.nsISupports))
+      return this;
+      
+    throw Components.results.NS_ERROR_NO_INTERFACE;
+  },
+  
+  notifyCertProblem: function certProblem(socketInfo, sslStatus, targetHost) {
+    // Silently ignore?
+    let log = Log4Moz.repository.getLogger("Service.CertListener");
+    log.level =
+      Log4Moz.Level[Utils.prefs.getCharPref("log.logger.network.resources")];
+    log.debug("Invalid HTTPS certificate encountered, ignoring!");
+
+    return true;
+  }
+};
diff --git a/services/sync/modules/service.js b/services/sync/modules/service.js
index d4243b9d028..acd5b130143 100644
--- a/services/sync/modules/service.js
+++ b/services/sync/modules/service.js
@@ -223,6 +223,7 @@ WeaveSvc.prototype = {
   set keyGenEnabled(value) { this._keyGenEnabled = value; },
 
   get enabled() Svc.Prefs.get("enabled"),
+  set enabled(value) Svc.Prefs.set("enabled", value),
 
   get schedule() {
     if (!this.enabled)
@@ -298,13 +299,13 @@ WeaveSvc.prototype = {
     let ok = false;
 
     try {
-      let svc = Cc["@labs.mozilla.com/Weave/Crypto;1"].
-	createInstance(Ci.IWeaveCrypto);
-      let iv = svc.generateRandomIV();
+      let iv = Svc.Crypto.generateRandomIV();
       if (iv.length == 24)
 	ok = true;
 
-    } catch (e) {}
+    } catch (e) {
+      this._log.debug("Crypto check failed: " + e);
+    }
 
     return ok;
   },
@@ -606,6 +607,9 @@ WeaveSvc.prototype = {
   _sync: function WeaveSvc__sync() {
     let self = yield;
 
+    if (!this.enabled)
+      return;
+
     if (!this._loggedIn) {
       this._disableSchedule();
       throw "aborting sync, not logged in";
@@ -661,6 +665,9 @@ WeaveSvc.prototype = {
   _syncAsNeeded: function WeaveSvc__syncAsNeeded() {
     let self = yield;
 
+    if (!this.enabled)
+      return;
+
     try {
 
       if (!this._loggedIn) {