diff --git a/src/apps/powerstatus/DriverInterface.cpp b/src/apps/powerstatus/DriverInterface.cpp
index c8b2b46451..3d070c0140 100644
--- a/src/apps/powerstatus/DriverInterface.cpp
+++ b/src/apps/powerstatus/DriverInterface.cpp
@@ -21,6 +21,7 @@ Monitor::~Monitor()
 status_t
 Monitor::StartWatching(BHandler* target)
 {
+	BAutolock autolock(fListLocker);
 	if (fWatcherList.HasItem(target))
 		return B_ERROR;
 
@@ -32,6 +33,7 @@ Monitor::StartWatching(BHandler* target)
 status_t
 Monitor::StopWatching(BHandler* target)
 {
+	BAutolock autolock(fListLocker);
 	return fWatcherList.RemoveItem(target);
 }
 
@@ -64,8 +66,6 @@ PowerStatusDriverInterface::~PowerStatusDriverInterface()
 status_t
 PowerStatusDriverInterface::StartWatching(BHandler* target)
 {
-	BAutolock autolock(fListLocker);
-
 	status_t status = Monitor::StartWatching(target);
 	
 	if (status != B_OK)
@@ -95,8 +95,6 @@ PowerStatusDriverInterface::StartWatching(BHandler* target)
 status_t
 PowerStatusDriverInterface::StopWatching(BHandler* target)
 {
-	BAutolock autolock(fListLocker);
-
 	if (fThreadId < 0)
 		return B_BAD_VALUE;
 
diff --git a/src/apps/powerstatus/DriverInterface.h b/src/apps/powerstatus/DriverInterface.h
index 5d271b9731..da6e55785c 100644
--- a/src/apps/powerstatus/DriverInterface.h
+++ b/src/apps/powerstatus/DriverInterface.h
@@ -42,6 +42,7 @@ public:
 	virtual void		Broadcast(uint32 message);
 
 protected:
+	BLocker				fListLocker;
 	WatcherList			fWatcherList;
 	
 };
@@ -72,8 +73,6 @@ private:
 	static int32		_ThreadWatchPowerFunction(void* data);
 
 	thread_id			fThreadId;
-	
-	BLocker				fListLocker;
 };
 
 
diff --git a/src/apps/powerstatus/PowerStatusView.cpp b/src/apps/powerstatus/PowerStatusView.cpp
index 56dad98ebb..57bc3a9764 100644
--- a/src/apps/powerstatus/PowerStatusView.cpp
+++ b/src/apps/powerstatus/PowerStatusView.cpp
@@ -400,7 +400,7 @@ PowerStatusReplicant::PowerStatusReplicant(BMessage* archive)
 
 PowerStatusReplicant::~PowerStatusReplicant()
 {
-	if (fExtWindowMessenger)
+	if (fMessengerExist)
 		delete fExtWindowMessenger;
 
 	fDriverInterface->StopWatching(this);
@@ -536,6 +536,7 @@ PowerStatusReplicant::_Init()
 	}
 	
 	fExtendedWindow = NULL;
+	fMessengerExist = false;
 	fExtWindowMessenger = NULL;
 
 	fDriverInterface->StartWatching(this);
@@ -566,7 +567,10 @@ PowerStatusReplicant::_OpenExtendedWindow()
 	msg.AddSpecifier("Hidden", int32(0));
 	if (fExtWindowMessenger->SendMessage(&msg) == B_BAD_PORT_ID) {
 		fExtendedWindow = new ExtendedInfoWindow(fDriverInterface);
+		if (fMessengerExist)
+			delete fExtWindowMessenger;
 		fExtWindowMessenger = new BMessenger(NULL, fExtendedWindow);
+		fMessengerExist = true;
 		fExtendedWindow->Show();
 	}
 	else
diff --git a/src/apps/powerstatus/PowerStatusView.h b/src/apps/powerstatus/PowerStatusView.h
index e4ebc7a85f..f3d7042898 100644
--- a/src/apps/powerstatus/PowerStatusView.h
+++ b/src/apps/powerstatus/PowerStatusView.h
@@ -86,6 +86,7 @@ class PowerStatusReplicant : public PowerStatusView
 		void			_OpenExtendedWindow();
 
 		BWindow*		fExtendedWindow;
+		bool			fMessengerExist;
 		BMessenger*		fExtWindowMessenger;		
 };