xps m1530 Laptop audio video problem playing DVDS

I have a Dell XPS M1530 Laptop Intel core 2 Duo Processor T8100 , 4GB Mem,32 bit operating Windows Vista Home Premium SP2. When I play a DVD it starts out playing then the sound starts and stops and the video does the same like it is slowly moving . I have updated the DVD drivers which is a optiarc DVD and also udated the Display drivers which is a NVidia GeForce 8600M GT thiss all on the suggestion of Dell and this did not help the problem suggested it was a software problem but they want to sock me big dollars to tell me how to fix the problem. this problem happens when using windows media player, Real Player  and from the windows media center. The computer is just 1 year old but I have had this problem ever since I purchased my computer don't know what to do has anyone else encountered this problem. I do have 2 other m1530s and they don't seem to have this problem. HELP!