ultranav/synaptics won't install vista pre-sp1

[cheeebs]

i have searched but cannot find this issue discussed...
machine is T60P 2613CTO, vista biz pre-sp1. my vista install is about 2 weeks old only.

vista auto-updated 2 days ago, and since then my middle button scrolling won't work on my touchpoint. i started the control panel to look at ultranav settings thinking they've been altered by the vista update, but when selecting control panel > mouse i get a "Synaptics driver failed to load." error.
uninstalled synaptics and ultranav, then reinstalled via thinkvantage... "1 package did not install".
attempted manual install of correct ultranav drivers from lenovo, and the synaptics driver won't install. i don't know what else to try. any suggestions, please?
... and thank you.