Recently was reported an ultra-lubricated system based on C-60 molecules deposited over graphite layers. In that work a stick-slip rolling model for C-60 molecules was proposed to explain the observed ultra-low friction force. In this Letter, we report the first molecular dynamics studies for these systems. Our results show that the AB stacking is not observed and the main experimental features can be explained without invoking stick-slip motions. (C) 2004 Elsevier B.V. All rights reserved.