Thanks to all for the suggestions! Here's the state of affairs:
> I'm not an expert but I would suggest that you also make sure the settings
> for your monitor are correct. It would not matter what your video card can
> deal with if you're driving your monitor at the wrong refresh rates and may
> actually be harmful for some monitors.
> I had that problem once when I had the scan rate/sync set too high for
> the monitor see if you can adjust that a bit.
I'm pretty sure these are fine. My monitor generally refuses to display if
the settings aren't correct. (I've tried to drive it at the wrong frequency
with my Mac, and it just goes into power-saving mode to protect itself.)
Also, if it were matter of the wrong sync, I'd rather expect to see problems
all the time, not just when things are moving around on screen. I guess I
could try another monitor to help narrow it down, though.
> What brand is your video card? I have noticed hardware instability on some
> under all op systems, often first apparent under X, but also presenting
> problems under win95 (sometimes a line of rainbow dots, sometimes a line
> of text underscored or mudded out, always a LOT of 95 crashes, which is why
> it is harder to notice there, since it is difficult to tell if a crash is
> Win95 or hardware) The worst offender seems to be the Cirrus Logic 9436
> and others of the 9xxx series.
The video is that which is built-in to the Dell Optiplex GMT5133 hardware.
Xconfigurator identifies it as an Trio 32/Trio 64 and wants to use the S3 X
Server for it. This brings up a good point: maybe I should try installing
one of those foul Windows operating systems to see if it's similarly
afflicted.
> It's throughly posible that you have a card thats never been tested, are
> you useing the SVGA server? (check 'ls -l /etc/X11/X')
/etc/X11/X -> ../../usr/X11R6/bin/XF86_S3*
Should I try switching to the SVGA server and see what happens?
And....errr...how would I go about doing that?
Thanks again, all!
Sean