Help! Problem with large M2ts files.

[Gregavi]

I've got the HD200 and am using it to play Blu ray movies that I have ripped using DVDFab into M2ts files that are usually around 25 GB in size for a standard movie. I have had some problems with a setup where I use a 2 TB drive connected to my server (WinXP OS-P4 2 GHz w/ 768 RAM). There was a time when playback was pretty good most of the time. Recently the video playback will pause, have audio dropouts and now is basically unwatchable. My network is not a Gigabit network so I assumed it was the fault of the speed of the network. I have now connected the 2 TB drive directly to the SageTV, bypassing the network. I have not seen much of an improvement, if any. Shouldn't I be able to play these videos in this method without any problems. A friend has suggested that I defrag my drive. I don't know if that will help...Any advice is appreciated.