Can't Resize Window using SetWindowPos

[Evets23]

Hi,
I'm developing on Windows XP and I need to resize a Remote Desktop window.
I'm using the following code:

try
{
   SetWindowPos(hwnd, HWND_TOP, 801, 2, 1000, 743, SWP_SHOWWINDOW);
}
catch(Exception ex)
{
  MessageBox.Show(ex.ToString(), "Resize Error", MessageBoxButtons.OK, MessageBoxIcon.Error);
}

The window does not get resized, but I do not get an exception. I know for sure that my hwnd is valid because the SWP_SHOWWINDOW brings the window to the forefront.

I've tested the code on Notepad and it works.

Do some windows classes impose resizing restrictions that my code does not address?

Thanks for your help,
Steve