Probably because of the bad poll yesterday? The one with Obama ahead 9 points?
This places operates off of the news of the day, not anything else. They also had Bush down on election day, because of the media’s bogus exit polls.
Bush went of around 23-24 (% chance of winning) for a while on election day in 2004. Bad bets and foreign money flow through Intrade at times, both showing precious little understanding of the ebb and flow of US politics and events (See: Palin to be withdrawn as VP pick).