The rule of thumb is once malware infected, System Restore and the like are not to be trusted and should be deleted immediately on detection of malware for both your own and others sanity.
Is there any way to delete all of the restore points?
I know when doing a system clean up you only get the option to delete all but the most recent restore point, (on XP Pro) and if there was anything lurking on the PC, surely it would make sense to wipe all previous stored points.