Players don't recognise all of the file - only with large MPG files

With a few mpg files that I have, as an example a 200Mb file running for about 18 minutes, the current Media player plays about 40 seconds of it and then stops. Sometimes individual frames are displayed after this, with sound, other times it stops completely.

This did not happen on previous versions of the windows media player (though it started about a year ago). I have finally had enough.

I have one computer that keeps playing the file (though the status bar is at 100%) and another which just stops when the status bar reaches the end. The latter is running XP and former ME.

I KNOW it is not a problem with the file as I have seen the entirety of it before. What’s more, i downloaded another version in case it had somehow been corrupted on my computer ... exactly the same thing happened.

Would very much appreciate help here.