Could be an honest mistake. The updating of the Multiple Listing Service is a manual effort by the listing agent. Note that many Boards of Realty require that the listing agent post any change in status within 24 hours, or they may be subject to stiff fines. Are you looking at a 3rd party site like Realtor.com, or HomeFinders.com? Those sites don't have direct feeds from the MLS systems and thus can be out of date, although the most I've seen them is about 3-4 weeks, not 2 months.