diff --git a/src/qtsingleapplication.h b/src/qtsingleapplication.h

index 049406f..aedd45e 100644

--- a/src/qtsingleapplication.h

+++ b/src/qtsingleapplication.h

@@ -78,6 +78,7 @@ public:

 #endif // QT_VERSION < 0x050000

     bool isRunning();

+    void setAppId(const QString &id);

     QString id() const;

     void setActivationWindow(QWidget* aw, bool activateOnMessage = true);

@@ -87,6 +88,8 @@ public:

     void initialize(bool dummy = true)

         { isRunning(); Q_UNUSED(dummy) }

+    void removeLockFile();

+

 public Q_SLOTS:

     bool sendMessage(const QString &message, int timeout = 5000);

     void activateWindow();

diff --git a/src/qtsingleapplication.cpp b/src/qtsingleapplication.cpp

index d0fb15d..9428a82 100644

--- a/src/qtsingleapplication.cpp

+++ b/src/qtsingleapplication.cpp

@@ -153,6 +153,8 @@ void QtSingleApplication::sysInit(const QString &appId)

 QtSingleApplication::QtSingleApplication(int &argc, char **argv, bool GUIenabled)

     : QApplication(argc, argv, GUIenabled)

+    , peer(0)

+    , actWin(0)

 {

     sysInit();

 }

@@ -166,6 +168,8 @@ QtSingleApplication::QtSingleApplication(int &argc, char **argv, bool GUIenabled

 QtSingleApplication::QtSingleApplication(const QString &appId, int &argc, char **argv)

     : QApplication(argc, argv)

+    , peer(0)

+    , actWin(0)

 {

     sysInit(appId);

 }

@@ -239,9 +243,13 @@ QtSingleApplication::QtSingleApplication(Display* dpy, const QString &appId, int

 bool QtSingleApplication::isRunning()

 {

-    return peer->isClient();

+    return (peer && peer->isClient());

 }

+void QtSingleApplication::setAppId(const QString &id)

+{

+    sysInit(id);

+}

 /*!

     Tries to send the text \a message to the currently running

@@ -258,7 +266,7 @@ bool QtSingleApplication::isRunning()

 */

 bool QtSingleApplication::sendMessage(const QString &message, int timeout)

 {

-    return peer->sendMessage(message, timeout);

+    return (peer && peer->sendMessage(message, timeout));

 }

@@ -268,7 +276,7 @@ bool QtSingleApplication::sendMessage(const QString &message, int timeout)

 */

 QString QtSingleApplication::id() const

 {

-    return peer->applicationId();

+    return (peer ? peer->applicationId() : QString());

 }

@@ -287,6 +295,10 @@ QString QtSingleApplication::id() const

 void QtSingleApplication::setActivationWindow(QWidget* aw, bool activateOnMessage)

 {

     actWin = aw;

+    if (!peer) {

+        return;

+    }

+

     if (activateOnMessage)

         connect(peer, SIGNAL(messageReceived(const QString&)), this, SLOT(activateWindow()));

     else

@@ -305,6 +317,11 @@ QWidget* QtSingleApplication::activationWindow() const

     return actWin;

 }

+void QtSingleApplication::removeLockFile()

+{

+    peer->removeLockedFile();

+}

+

 /*!

   De-minimizes, raises, and activates this application's activation window.

@@ -326,6 +343,7 @@ void QtSingleApplication::activateWindow()

         actWin->setWindowState(actWin->windowState() & ~Qt::WindowMinimized);

         actWin->raise();

         actWin->activateWindow();

+        actWin->setFocus();

     }

 }

diff --git a/src/qtlocalpeer.h b/src/qtlocalpeer.h

index 2ff1512..6a5e57e 100644

--- a/src/qtlocalpeer.h

+++ b/src/qtlocalpeer.h

@@ -57,6 +57,7 @@ public:

     bool sendMessage(const QString &message, int timeout);

     QString applicationId() const

         { return id; }

+    void removeLockedFile();

 Q_SIGNALS:

     void messageReceived(const QString &message);

diff --git a/src/qtlocalpeer.cpp b/src/qtlocalpeer.cpp

index 5a2abf9..321f861 100644

--- a/src/qtlocalpeer.cpp

+++ b/src/qtlocalpeer.cpp

@@ -159,6 +159,10 @@ bool QtLocalPeer::sendMessage(const QString &message, int timeout)

     return res;

 }

+void QtLocalPeer::removeLockedFile()

+{

+    lockFile.remove();

+}

 void QtLocalPeer::receiveConnection()

 {