I have been having the same problem that all of you are with the choppy and skipping movies.
Current System Specs:
AMD Athlon TB 850
Asus KT-133 Mainboard
256 MB PC133 SDRAM
nVidia GeForce 2 MX-400 32 MB AGP
Gamesurround Fortissimo 2 PCI Audio
56x CD Rom max
30 GB 5200...