(im using maya 7.0 btw)
wow it works ... why isnt it happen to me! arrghh...

i wanted to see and fiddle around with the scene to see if i can try to create a ball and attach gravity to it and this is what happends...

i created a sphere and attached gravity to it, at 0.1 seconds i see at the bottum right the error come up but then another one comes up, "Error: No object matches name: |". i also added create active riggid body to the new sphere and now when i play the scene, after both of the balls hit the ground my ball just starts to rise slowly like theres no gravity?