diff --git a/src/main/scala/com/github/shadowsocks/BaseService.scala b/src/main/scala/com/github/shadowsocks/BaseService.scala
index e955d2e1..19da9814 100644
--- a/src/main/scala/com/github/shadowsocks/BaseService.scala
+++ b/src/main/scala/com/github/shadowsocks/BaseService.scala
@@ -49,8 +49,8 @@ import android.content.Context
 
 trait BaseService {
 
-  var state = State.INIT
-  var callbackCount = 0
+  @volatile var state = State.INIT
+  @volatile var callbackCount = 0
 
   final val callbacks = new RemoteCallbackList[IShadowsocksServiceCallback]
 
@@ -105,15 +105,17 @@ trait BaseService {
     handler.post(new Runnable {
       override def run() {
         if (state != s) {
-          val n = callbacks.beginBroadcast()
-          for (i <- 0 to n - 1) {
-            try {
-              callbacks.getBroadcastItem(i).stateChanged(s, msg)
-            } catch {
-              case _: Exception => // Ignore
+          if (callbackCount > 0) {
+            val n = callbacks.beginBroadcast()
+            for (i <- 0 to n - 1) {
+              try {
+                callbacks.getBroadcastItem(i).stateChanged(s, msg)
+              } catch {
+                case _: Exception => // Ignore
+              }
             }
+            callbacks.finishBroadcast()
           }
-          callbacks.finishBroadcast()
           state = s
         }
       }
diff --git a/src/main/scala/com/github/shadowsocks/Shadowsocks.scala b/src/main/scala/com/github/shadowsocks/Shadowsocks.scala
index cbaa4686..b0db7bf5 100644
--- a/src/main/scala/com/github/shadowsocks/Shadowsocks.scala
+++ b/src/main/scala/com/github/shadowsocks/Shadowsocks.scala
@@ -507,7 +507,7 @@ class Shadowsocks
       val intent = new Intent(this, s)
       intent.setAction(Action.SERVICE)
       bindService(intent, connection, Context.BIND_AUTO_CREATE)
-      if (!isVpnEnabled) startService(new Intent(this, s))
+      startService(new Intent(this, s))
     }
   }
 
diff --git a/src/main/scala/com/github/shadowsocks/ShadowsocksNatService.scala b/src/main/scala/com/github/shadowsocks/ShadowsocksNatService.scala
index a799f4a8..4357c001 100644
--- a/src/main/scala/com/github/shadowsocks/ShadowsocksNatService.scala
+++ b/src/main/scala/com/github/shadowsocks/ShadowsocksNatService.scala
@@ -309,6 +309,11 @@ class ShadowsocksNatService extends Service with BaseService {
     }
   }
 
+  override def onStartCommand(intent: Intent, flags: Int, startId: Int): Int = {
+    Service.START_NOT_STICKY
+  }
+
+
   def killProcesses() {
     Console.runRootCommand(Utils.getIptables + " -t nat -F OUTPUT")
 
@@ -328,10 +333,6 @@ class ShadowsocksNatService extends Service with BaseService {
     Console.runCommand(ab.toArray)
   }
 
-  override def onStartCommand(intent: Intent, flags: Int, startId: Int): Int = {
-    Service.START_STICKY
-  }
-
   def flushDNS() {
     Console.runRootCommand(Array("ndc resolver flushdefaultif", "ndc resolver flushif wlan0"))
   }
@@ -453,9 +454,7 @@ class ShadowsocksNatService extends Service with BaseService {
     filter.addAction(Action.CLOSE)
     receiver = new BroadcastReceiver() {
       def onReceive(p1: Context, p2: Intent) {
-        spawn {
-          stopRunner()
-        }
+        stopRunner()
       }
     }
     registerReceiver(receiver, filter)
@@ -580,7 +579,6 @@ class ShadowsocksNatService extends Service with BaseService {
 
   override def stopBackgroundService() {
     stopRunner()
-    stopSelf()
   }
 
   override def getTag = TAG
diff --git a/src/main/scala/com/github/shadowsocks/ShadowsocksVpnService.scala b/src/main/scala/com/github/shadowsocks/ShadowsocksVpnService.scala
index 464f771a..6e19bfdd 100644
--- a/src/main/scala/com/github/shadowsocks/ShadowsocksVpnService.scala
+++ b/src/main/scala/com/github/shadowsocks/ShadowsocksVpnService.scala
@@ -253,7 +253,10 @@ class ShadowsocksVpnService extends VpnService with BaseService {
 
     notificationManager = getSystemService(Context.NOTIFICATION_SERVICE)
       .asInstanceOf[NotificationManager]
+  }
 
+  override def onStartCommand(intent: Intent, flags: Int, startId: Int): Int = {
+    Service.START_NOT_STICKY
   }
 
   override def onRevoke() {
@@ -295,9 +298,7 @@ class ShadowsocksVpnService extends VpnService with BaseService {
     filter.addAction(Intent.ACTION_SHUTDOWN)
     receiver = new BroadcastReceiver {
       def onReceive(p1: Context, p2: Intent) {
-        spawn {
-          stopRunner()
-        }
+        stopRunner()
       }
     }
     registerReceiver(receiver, filter)