Its the wires underneath the front passenger seats, if you move them back and forth a lot for rear passengers to get in, then those connectors(orange wires) can get loose.These wires control the airbag and seat belt tensioners.Just check the connections are ok,push the connectors together then the light should go out next time you start the ignition(after its initail check. By the way, the light comes on to warn that there is a fault with the airbag system and not that the airbag is about to go off!!
VTR Rob, October 2006
