MP4Box outputting files unplayable in WMP

[zdvd]

I can play MP4 files encoded with handbrake in media player but if I try to play a file run through MP4Box with the splitx option (to pull out a chunk of video with a given start and end time) the output is not playable in WMP. I also don't get thumbnails and video details in explorer once it has been run through MP4Box. It is playable in QuickTime but I need it to play in WMP (on Windows 7).

I don't get why this is happening since it is not reencoding anything (right?) so I don't see why a codec support problem would develop from the splitting operation. Maybe there is something wrong with the container? Is there an option I need to use to maintain compatibility with WMP? Is there a better tool to use to cut up a MP4 into smaller MP4s without changing anything else?

[Baldrick]

That sounds strange. Maybe you could try run the mp4 through avidemux(use video and audio copy settings) and see if it creates a different mp4.