Mdeiagate MG-350HD Streaming DVD Problem

I have a 350HD that will stream everything thing fine via hard wired ethernet, but DVD Movie files. I have tried ISO, IFO, and VOB files. It starts to stutter after usually a half hour into the movie. I have modded Xbox which streams fine in another room. I have a internal hard drive in the 350HD which plays ripped dvd fine, and also an external usb drive, but I want to pull them from my network drives too. I have tried wireless and now wired with the 350hd and still have the same problems. Anyone else have the same problems, or a idea for a fix on this?