Thanks to SuperDuper, I just avoided having to reinstall Leopard (AND ALL THE UPDATES) after using a BAD Epson Installer. (Bad Installer, bad: Go to your room 🙂
This is the type of problem (System file corruption) that would be quite tricky (at best) to reverse using Time Machine.
The salient point is that I’m encouraged to make freqent backups, because SuperDuper is painlessly quick!
SuperDuper; It really is.