Windows Media Player defaults to one channel (not mono)

When I play videos (mpegs recorded off TV Tuner), It defaults to one channel. Not mono, but the right (or left) channel of stereo.

Each time I start a new show, I have to go and manually change it to stereo.
I went into preferences, everything is set to stereo.

I go to; Right click on the player, "Play" "Audio..." It has "stereo ", "Right channel ", "Left Channel. "

Why does it do this? How can I get it to stay on Stereo?

Thank you,
Chris.

 

Anybody?