What are your system specs, OS etc?
Using a Nvidia product, I would suggest using the 21.81 drivers for DVD playback.Celeron 633 @ 1064 , Windows XP server,
Pentium 3 1000 @ 1100,Abit bx-133, 256 Mb Mushkin Rev.3 cas 2-2-2, ATI Radeon
AMD Thunderbird 1.4 @ 1.63 (24/7) IWILL KK266R , Corsairs pc 150 cl2, Leadtek GeForce 3 