redisplay draws outside of window bounds on Windows

redisplay draws outside of window bounds on Windows

[andrew.maguire]

On redisplay, portions of the current emacs buffer are redrawn outside of
the normal window
bounds. It is as though the redisplay code is using a top left window
position of 0, 0.
Doing a Ctrl-L to recenter cures the problem but only for a little while.
Also when trying to move the window, the new window bounds are not displayed
(when "show window contents" option is off).
The problem appears to be limited to just the redisplay of Emacs, other
windows and applications are
unaffected.

It has been experienced on Windows 2000 and Windows NT with
graphics cards: Matrox G450 AGP and Matrox G400 AGP.

I have been unable to reproduce this behaviour on Windows NT with a Diamond
Fire GL 1000 PRO.

I was wondering if anyone else had seen this behaviour since I would have
thought it would be
a graphics card issue rather than a bug in Emacs...

TIA,
Andrew

P.s. I have also seen a redisplay problem when running Emacs 20 from Unix
via Exceed
on Windows NT using a NVidia Riva TNT2. However, in the cases when Exceed is
involved,
*all* window widgets get redrawn relative to 0,0 including the Start button
and the task bar
and other open running applications are affected.