C# System.Drawing Graphic Not implemented exception

The following code compiles, but when the method is called I get System.NotImplementedException: Not implemented. I'm not using custom classes.

private void miterTopLeft(Image img, Graphics gfx)
{
    int maxSize = Math.Max(img.Height, img.Width);
    Point[] points = new Point[4];
    points[0] = new Point(0, 0);
    points[1] = new Point(maxSize, maxSize);
    points[2] = new Point(0, maxSize);
    points[3] = new Point(0, 0);
    gfx.DrawImage(img, points);
}

Why is this error occuring in a .NET class? Is there a work around?

Stack Trace:

[NotImplementedException: Not implemented.]
System.Drawing.Graphics.CheckErrorStatus(Int32 status) +1154064
System.Drawing.Graphics.DrawImage(Image image, PointF[] destPoints) +150
GetMergeImage.miterTopLeft(Image img, Graphics gfx) in d:\.NET Projects\publish2\GetMergeImage.ashx:51
GetMergeImage.drawLeftBorderRectangeRug(Double ppi, Boolean hasCorner, Graphics gfx, DesignVO border, Image img, Double vBorderStartY, Double vBorderStartX, Double vBorderNumRepeat) in d:\.NET Projects\publish2\GetMergeImage.ashx:243
GetMergeImage.drawRectangularRug(Int32 displayWidth, Int32 displayHeight, Int32 width, Int32 height, MergeVO merge) in d:\.NET Projects\publish2\GetMergeImage.ashx:140
GetMergeImage.ProcessRequest(HttpContext context) in d:\.NET Projects\publish2\GetMergeImage.ashx:40
System.Web.CallHandlerExecutionStep.System.Web.HttpApplication.IExecutionStep.Execute() +100
System.Web.HttpApplication.ExecuteStep(IExecutionStep step, Boolean& completedSynchronously) +75
开发者_JS百科

According to the documentation you can only pass three points that make up a parallelogram.

If you want a triangle you will need to clip the drawing