DVD player pauses every few seconds?!

Just upgraded my PowerBook to Leopard. I've heard of a few problems with DVD player, but not this one-- approximately every 8 seconds, the DVD player pauses. Not freezes or hangs, but goes into Pause mode, as if I'd clicked the Pause button. Even happens while fast forwarding or rewinding!

Anyone else seen this, or have any suggestions (other than using VLC?!)