system.drawing. dll - Invalid parameter used

[Martin]

I have Panel embedded in a Form. The panel has a PaintEventHandl er to
catch PaintEvents. When a PaintEvent occurs a new Thread which moves a
Ellipse should be created.

The Code:

private void pnlTest_Paint(o bject sender, System.Windows. Forms
PaintEventArgs e)
{
if(.....)
{
this.graphics = e.Graphics;
Thread t = new Thread( new ThreadStart(thi s.draw) );
t.Start();//throws Exception
}
}
private void draw()
{
this.graphics.F illEllipse( new SolidBrush(Colo r.Red),10,10,30 ,30);
//should move the Ellipse later
}

When running the Application I get the following Error Message:

An unhandled exception of type 'System.Argumen tException' occurred in
system.drawing. dll
Additional information: Invalid parameter used.

When I call the draw Method directly without creating a Thread it
works fine.

private void pnlTest_Paint(o bject sender, System.Windows. Forms
PaintEventArgs e)
{
if(.....)
{
this.graphics = e.Graphics;
this.draw();//works fine
}
}
Any Ideas?

Thanks