Serial Port Close Problem in Pocket PC

[HosseinSadeghi]

Hello,

This is a code about serial port connection in POCKET PC. This code uses serial port Data_Recive Event. When data enter the input buffer it is read and shown in logTextBox.

Problem: When I want to close the port, the system freezes completely.
I am using .net compact framework 2.0 Sp2 and visual studio.net 2005 and
C# language.

Thanks,
Sadeghi

public partial class MainForm : Form
    {
        private Delegate UpdateHandler;      
private void DoUpdate(Object s, EventArgs e)
        {
            logTextBox.Text += ReadLineBuffer;
        }
private void serialPort_DataReceived(object sender, System.IO.Ports.SerialDataReceivedEventArgs e)
        {
            ReadLineBuffer = serialPort.ReadLine();
            this.Invoke(UpdateHandler);
        }

      private void MainForm_Load(object sender, EventArgs e)
        {
            serialPort.Handshake = Handshake.None;
            UpdateHandler = new EventHandler(DoUpdate);
        }
  private void connectMenuItem_Click(object sender, EventArgs e)
        {
            if (serialPort.IsOpen == false)
            {
                try
                {
                    serialPort.Open();
                    this.serialPort.DataReceived += new System.IO.Ports.SerialDataReceivedEventHandler(this.serialPort_DataReceived);
                }
                catch(IOException Exeption)
                {
                    MessageBox.Show(Exeption.Message, "Error", MessageBoxButtons.OK, MessageBoxIcon.Hand,MessageBoxDefaultButton.Button1);
                }


}

    private void disconnectMenuItem_Click(object sender, EventArgs e)
        {
            if (serialPort.IsOpen == true)
            {
                try
                {
                    serialPort.DiscardInBuffer();
                    serialPort.DiscardOutBuffer();
                    this.serialPort.DataReceived -= new System.IO.Ports.SerialDataReceivedEventHandler(this.serialPort_DataReceived);
                    serialPort.Close(); //Error
                }
                catch (IOException Exeption)
                {
                    MessageBox.Show(Exeption.Message, "Error", MessageBoxButtons.OK, MessageBoxIcon.Hand, MessageBoxDefaultButton.Button1);
                }
            }
        }