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