.NET Base: Mutex Problem - .NET Base

 	internal static Mutex mutexInstance = null;
 	private const string MutexID = "tkmap";
 	[STAThread]
 	internal static void Main()
 	{
 	
 	try
 	{
 	mutexInstance = Mutex.OpenExisting(MutexID);
 	messageBoxEx.Show(null, "Instanzproblem", "Nur eine Instanz erlaubt!",
 	"Es läuft bereits eine Instanz von TKMap!", MessageBoxButtons.OK,
 	MessageBoxIcon.Exclamation);
 	Environment.Exit(0);
 	}
 	catch
 	{
 	mutexInstance = new Mutex(true, MutexID);
 	}

 	mutexInstance.ReleaseMutex(); 	Application.Run(Loader);

[STAThread]
        static void Main()
        {
            Application.EnableVisualStyles();
            Application.SetCompatibleTextRenderingDefault(false);
            
            bool isNew = false;
            System.Threading.Mutex appMutex = new System.Threading.Mutex(
                true,
                "e65be7a5-9579-49af-a4f6-5dab130be5e1",
                out isNew);

            if (isNew)
            { 
                Application.Run(new Form1());
            }
            else
            {
                MessageBox.Show("Autschn!");
            }
            
        }

 	private const string MutexID = "tkmap";
 	[STAThread]
 	internal static void Main()
 	{
 	Application.EnableVisualStyles();
 	Application.SetCompatibleTextRenderingDefault(false);

 	AppDomain currentDomain = AppDomain.CurrentDomain;
 	currentDomain.AssemblyResolve += new ResolveEventHandler(currentDomain_AssemblyResolve);

 	bool isRunning = false;
 	Mutex appMutex = new Mutex(true, MutexID, out isRunning);

 	if (isRunning)
 	{
 	messageBoxEx.Show(null, "Instanzproblem", "Nur eine Instanz erlaubt!",
 	"Es läuft bereits eine Instanz von TKMap!", MessageBoxButtons.OK,
 	MessageBoxIcon.Exclamation);
 	Environment.Exit(0);
 	}
 	else
 	{
 	[...]
 	}