Not specifically helpful to you, but I don't put a lot of stock in 'System Restore' on XP. Here's why:

Brand new Dell Optiplex SX280. XP Pro SP1. I get it set up, set a restore point (completely fresh system, only the pre-loaded software, namely Office & Acrobat). I install a USB modem, start getting bluescreens due to a crap driver from the manufacturer (Zoom I believe). I do a system rollback, I still get bluescreens. I have to re-run setup from the System Restore disks (aka Nuke from High Orbit) to fix it. If it won't work in a pristine system, how well will it work on a well-used box?

I haven't used it since.

-Zeke