DVD playback problems!!!s.o.s.!!!

[dowland7]

I just bought a BTC 12x dvd and i own a P celeron at 433 with 192 mb ram 4.5gb hdd , a GeForce 2 mx400 w/ 64mb ram grafix card and a sound blaster live!
I tried to watch a movie (Joan Of Ark) and the speed quality is really bad!!it seems it shows the half frame speed!!! a friend of mine has a P celeron 300 w/ 64mb ram 4.5gb hdd,an unknown 16mb ram graphics card and a hitachi dvd 4x and the quality is amazing!!!!!What's wrong with the speed quality????
please help me because i just bought it and i don't know what to do!!! is the dvd bad?? (it's BTC 12x)

[UncasMS]

make sure DMA is enabled

[Cpt.Crunch]

Also make sure you have a minimal amount of programs running in the taskbar.