XWin fails to render KDE properly

["CB Genrich" <cbgenrich at yahoo dot com>]

I have this working on a similar XP box across the room.
But can't get it to work on this XP box.
 
This one has an NVIDIA GeForce2 MX/400 and also an
NVIDIA GeForce2 MX/100.  Two display adapters, two
monitors.
 
XWin gets and renders a Linux XDM login screen properly.
 
After login, the KDE splash screen isn't properly rendered,
and so it goes for much of KDE.
 
We're talking KDE 3.0.  The splash screen sequences
through a half dozen little icons and writes a text description
at the bottom of the splash screen as it progresses.
 
The problem is first observed in that the icons are not shown
and the text messages over-write one another without erasing
the previous ones.  The KDE desktop is rendered but almost
no icons are shown.  etc.
 
The working XP box had the same problem and it was resolved
when I went to XWin -fullscreen -depth 24 (as I recall).
 
Can someone suggest a path for me to take to get this
working?
 
-CB-  cbgenrich@yahoo.com