[2.0] Custom border form problem (Advanced. Guru needed)

[BrianHawley]

I'm having a problem processing the WM_NCCALCSIZE message to redefine the border widths of a form.

This is the code:

    private void WmNCCalcSize(ref Message m)
    {
      if (m.WParam.ToInt32() == 0)
      {
        RECT rc = (RECT)m.GetLParam(typeof(RECT));
        rc.Left += 120;
        rc.Top += 20;
        rc.Right -= 20;
        rc.Bottom -= 20;
        Marshal.StructureToPtr(rc, m.LParam, true);
        m.Result = IntPtr.Zero;
      }
      else
      {
        NCCALCSIZE_PARAMS csp;
        csp = (NCCALCSIZE_PARAMS)m.GetLParam(typeof(NCCALCSIZE_PARAMS));
        csp.rgrc0.Top += 120;
        csp.rgrc0.Bottom -= 20;
        csp.rgrc0.Left += 20;
        csp.rgrc0.Right -= 20;
        Marshal.StructureToPtr(csp, m.LParam, true);
        //Return zero to preserve client rectangle
        m.Result = IntPtr.Zero;
      }
    }

Works perfectly - that is until the user maximizes and normalizes the form, then the size of the @#!##@% form changes! i.e. it does not restore to the proper size.

It's driving me nuts.

A small and rather messy project illustrating the problem is attached. Sorry, it's a rar as I don't have WinZip on this machine.

Any ideas? Can it be a DotNet bug?

Help!!!!