Looking at this, along with the "Blue Screen" issue with windows update, only affecting XP users
last year, a few XP users caught a virus off windows update, microsoft did say "sorry we was hacked" as well as "use vista it wont happen"
the bigger picture is, it all seems to be XP users that have problems off windows update, like its aimed at XP machines as an encouragement to upgrade to vista or windows 7,
maybe im just paranoid, but i dont trust windows update as much as i trust a rattlesnake not to bite me.