Short video stream

Hi All
Hope someone can help me.

I have a video stream that seems to have a problem with the embedded timecode. When imported as an asset into DVD Maestro, it comes up shorter by about 20 minutes to the audio file. I have authored it to see what the result would be, and as expected, the resulting movie loses the last 20 minutes.
If i play the video stream with windows media player, i can see the whole movie, but the time still shows as 20 minutes shorter than it should be.

Does anyone know how i can adjust the timecoding of this video stream ( .m2v format)