Difficulty of Robot Challenges

In CWorld: Robots have been able to do some very impressive things lately.  But it is often hard to make them do specific tasks that human can do autonomously.  In a recent challenge:  " ... NASA officials and roboticists were disappointed, but not shocked, at the less-than-spectacular results at yesterday's NASA robotics challenge -- even though researchers from the likes of Rensselaer Polytechnic Institute, Worcester Polytechnic Institute (WPI) and Oregon State University had worked on the fully autonomous machines. ... "