Movement in TextOut. Why?

Hello once again, Newsgroupians:

I've another question relating to drawing on a DC.

Joseph Newcomer has been very instrumental in assisting me; however, I am
stuck once again.
I am trying to write some text at the bottom of the client area. I do not
know the length of the string that I am going to write at the bottom, so I am
using GetTextExtent to determine the length of it and position it
accordingly. However, when someone drags and moves the window, the text is
moving VERTICALLY!

I have the following code in my OnPaint handler for a CFormView.

void CRalView::OnPaint()
{
  CPaintDC dc(this);

  CRect rect;
  GetClientRect(&rect);

  // Change the map to +x to the right and +y is up.
  // Change the origin to the bottom-left of the client
  dc.SetMapMode(MM_ANISOTROPIC);
  dc.SetWindowExt(32767, 32767);
  dc.SetViewportExt(rect.right, -rect.bottom);
  dc.SetViewportOrg(0, rect.bottom);

  // Create a font at a 90 degree angle to the horizontal axis
  // Also, make the average width to be 1000 device points
  CFont vertFont;
  vertFont.CreateFont(1000, 0, 900, 900, ...);

  // Select the new font
  CFont *pOrigFont;
  pOrigFont = dc.SelectObject(&vertFont);

  // Calculate the height extent of the string
  CSize ext;
  ext = dc.GetTextExtent(CString(_T("Hello"));

  // Output the text at the bottom
  dc.TextOut(10000, ext.cx, CString(_T("Hello")));
  dc.SelectObject(pOrigFont);
}

Now, why does the text move VERTICALLY when someone is resizing the window
HORIZONTALLY?

I know GetTextExtent() assumes the text to be horizontal, but the device
points for the created font is 1000. Therefore, shouldn't GetTextExtent()
always return the same number if the string being passed to it is always a
constant, for the extents of the window are not changing?

Thank you, Newgroupians, for your continued guidance and help.

Trecius