This laptop uses a Chips and Technologies F65550 (rev 198) VGA controller. 
The preferred video mode is 800x600x24.

Xconfigurator inserted "DefaultColorDepth 32" for this chip, limiting it to
a rather ugly 640x480 resolution.

I would like to revisit the issue of separately listing resolutions for
depth 24 and depth 32, in addition to 8bps and 16bps, instead of having
Xconfigurator keep track of which video cards use depth 24, and which video
cards use depth 32 for 24bps video mode.  This takes a whole bunch of
guesswork out of Xconfigurator.

Also, when multiple resolutions are selected for the same video mode, they
are written out into XF86Config with the lowest resolution listed first. 
This results in X starting in the lowest resolution mode.  It's probably
better to reverse the order of the resolutions, and have X start in the
highest resolution selected.

It might even be worthwhile to simplify this even further, and simply
generate all the possible resolutions, from highest to lowest.  Since X
automatically deletes resolutions it can't support for the video card, this
results in X being automatically configured for the highest possible
resolution available in the hardware.  Just have Xconfigurator prompt for
the video depth mode, and use that to initialize
defaultcolordepth/defaultdepth.