Updating a Form from a serial port event (Please, very urgent)

Question

Hi all,

First of all, sorry for adding the (Very Urgent) to the title.

We have to demo this program in 4 hours and everything is working but the updating of the display.

I have a bitmap displayed in a Graphics Rectangle.

I manually set the pixels of the bitmap based on info coming in from the serial port.

When I have received 98 values, I want to redraw the scene, I get a "System.ArgumentException: Parameter is not valid" exception:

gForm.DrawImage(bmp, 10, 10, bmp.Width, bmp.Height);

So I'm thinking that the problem is cross thread calling so I tried:

this.Invoke(new EventHandler(delegate { gForm.DrawImage(bmp, 10, 10, bmp.Width, bmp.Height); })); 

I also tried the proper way

this.Invoke(new DoUpdateForm(UpdateForm), bmp);

[...]

private delegate void DoUpdateForm(Bitmap bmp);

private void UpdateForm(Bitmap bmp)

{

gForm.DrawImage(bmp, 10, 10, bmp.Width, bmp.Height);

}

But the error keeps appearing.

I run the exact same method when I first paint the Form and it works fine.

I am working with VS2010 for the first time so I thought it may have been a change from .net 3.5 to .net 4 so I switched back to .net 3 but it still doesn't work.

Please help!! 

Thanks a mil in advance

Paul

ps->The entire code is attached