If I understand you correctly you are still using the 2 year old
version of Ubuntu. Please consider updating to 10.04 (Lucid) as it
should solve many of your problems. Being a Long Term Support version
it is more stable and capable than what you have.

Not quite correct. I was using v. 10.04 when the problems began following, if
you remember, a couple of updates downloads. I had had issues with Lucid before
and had considered going back to Karmic because I felt it was more stable. As I
moved up through the various upgrades, I had few problems until 10.04.

I'm the prexy of our community's computer club (all they needed was a warm body
to run the meetings, not expertise) and had been pushing U for converts. At this
point, I'm keeping quiet.

I'm back at 9.04 'cause I've done only one update since doing the cold-turkey
re-install from the Live CD I got from Canonical back when. (I subsequently
updated primarily to get rid of that hideous skull-like desktop on 8.10. Or was
it the satin from a coffee cup?)

In that case you really owe it to yourself to try out other distros. Some
are famous for working with difficult hardware. Check out
www.distrowatch.com

If you updated from 9.04 to 9.10 to 10.04 then that's more than likely
the root cause of the troubles you've been having. Question is, now
you have 9.04 back on does everything work again or is the trackpad
still AWOL ?

You'd be better advised downloading the ISO for 10.04 and creating the
boot CD for it then installing that as it's fully supported for 3
years as opposed to the normal development cycle of 6 months between
upgrades. That way you won't need to even think of upgrades ( but will
still get the normal updates and patches ) until April 2013