frame-pixel-width returns incorrect value (CVS Emacs on Windows XP)

[Francis Litterio]

Using CVS Emacs on Windows XP, evaluate the below form in a frame that
is _not_ currently 60 columns wide by 20 rows high.  The values in the
resulting list are equal, but they should not be.

   (let ((origwidth (frame-pixel-width (selected-frame))))
     (modify-frame-parameters nil '((width . 60) (height . 20)))
     ;;(sit-for 0)
     (list origwidth (frame-pixel-width (selected-frame))))

If you uncomment the call to sit-for, the values in the resulting list
are different (as they should be).

It appears that the second call to frame-pixel-width is unaware of the
change to the width of the frame made by modify-frame-parameters.

The same problem happens with frame-pixel-height.  I don't know if this
is unique to Windows, since I don't have access to a Linux box right now.
--
Fran