He's got little bug on there that's hiding itself good. Hopefully Vundofix will get rid of it. The descriptions found on this one are like the one seen at the f-secure.com link where it will create new entries and change file names to keep itself hidden. After you see the host file removed post a few followup logs after a few days to see what else comes up. You'll probably hear: "Not this crap again... come on!
ggrrrr... ". It works like a self duplicating I-Worm.