Bumping a two year old thread, but WTH...
I'm downgrading a 5420 to XP Home and googled for some drivers. This thread was the first to show up. I downloaded all the drivers from the FTP site as linked in post #3. Everything worked but the video.
I ended up going to Acer's site and finding it, and others.
Choose Window XP Home 32-bit from the dropdown and get the video driver. Worked great for me. Device Manager is squeaky-clean now!