I'm not sure how to help you with your problem, but I have to question whether installing Vista on an Aspire One is the best idea. Perhaps you own a newer model than mine and they've made some massive upgrades in terms of RAM and the Graphics chip, but barring that (and possibly even then) I don't think Vista would run very well at all. MAYBE with every graphical effect possible turned off you'd get some decent performance, but I'm not sure even that would make it run as well as XP does.

Maybe someone who knows more about the Aspire One's current specs could weigh in.