Windows ProgressBar not working on all XP and none 2000 PCs

I simply drag-n-drop a progressbar onto a windows app, however I do start it a bit unusually but it still works fine on the XP Development PC both within VS2005 C# debugging and just as a stand-alone app outside the VS IDE. Here's some code on starting and stopping that makes the progressbar visible then not visible when it's instructed to stop.

Note: A windows 2000 PC will show the progressbar only as a slim white rectrangle without any progress tick, however it does at least make visible then not visible.
Note: A XP Pro PC (other than my XP VS2005 PC) nothing shows at all

I'm puzzled....... :-(


         private void button1_Click(object sender, System.EventArgs e)
        {
            try
            {
                Application.DoEvents();
                ProgressbarStatus(100);
               
                // Do some time consuming work on a seperate Thread like loading a listview from a database

               Application.DoEvents();
               ProgressbarStatus(0);                  
            }
            catch (Exception ex)
            {
                MessageBox.Show(ex.ToString());            
            }
        }

         private void ProgressbarStatus(int speed)
        {
            if (speed > 0)
            {
                progressBarStatus.Enabled = true;
                progressBarStatus.Visible = true;
                progressBarStatus.BackColor = Color.AliceBlue;
                progressBarStatus.Minimum = 0;
                progressBarStatus.Maximum = 100;
                progressBarStatus.Style = ProgressBarStyle.Marquee;
                progressBarStatus.MarqueeAnimationSpeed = speed;

                Application.DoEvents();
            }
            else
            {                
                progressBarStatus.Style = ProgressBarStyle.Marquee;
                progressBarStatus.MarqueeAnimationSpeed = speed;
                progressBarStatus.Visible = false;

                Application.DoEvents();
            }
        }