rigid bodys keep getting stuck

hello im trying to make a train run along a track. the wheels are attached to the the body with rigid body joints and all the objects are rigid body. but the train keeps getting stuck when moving along the track and the only way i get it to go over the track without stopping is setting the force really high but by then it’s going too fast to be any good for a train. here is the blend http://www.mediafire.com/download.php?jonhztnuzmt. can any body figure out what im doing wrong. or is it just my operating since this worked fine until we got windows 7.

You can try adjusting the friction settings of your materials. These can be found by pressing DYN in the material tab.

Good luck


this seems to have worked