cannot play commercial DVD'S on DVD Writer

[Gaudi66]

Hello, first of all i would like to thank this formum for helping me a lot with my DVD Writer ( authoring etc.) I can make and play dvd-r's without any problem.
However i cannot play commercial DVD's the video is very jumpy or sometimes there is no video at all, the sound is distorted. I use WinDVD to play the DVD's.
I even formated my harddrive and reinstalled win 2k. same difference.
if i use Shrink to rip the DVD's onto the harddrive i can play them with no problems.

[jtoolman2000]

What's the speed of your processor?

[Gaudi66]

P4 2.6Ghz 512kRam 800FSB, Video Card Geforce FX5200 128mb Ram

[handyguy]

Is DMA turned on? Cause it makes things go alot faster if it is.

[Gaudi66]

I think it is in the devicemanager under Secondary IDE Channel where the Drive is connected as a master ( there is no Slave mounted ) it says current transfer mode "ULTRA DMA MODE"
Also Strange is that the DVD-R's Play perfectly and if i copy the commercial DVD onto The Harddrive they play fine so it seams the DVD Writer can read them at least ?

[Gaudi66]

Is there any way to test the DMA Setting?
I notice that if i copy an MPEG File from a regular CD-R It is a lot faster from my CD rom Drive(52x read) than from my DVD writer (40x CD read)
700 Mb take about one minute to copy to the harddrive from the CD Rom, about 10Minutes from the DVD Writer?