Display cutting edge off image

I have been happily running Media Centre on a media centre PC.

Recently, Media Centre has started to subtly stretch the image, cutting the right and left edge off the image.

At first I thought it was my television, but all the menu items are all within the display. it is only the DVD image itself that is stretching.

The problem has become quite annoying so I now play my DVDs through WMP or PowerDVD but I cannot use my Media Centre remote for those programs.

Any idea of a fix?

I cannot find any relevant display controls in settings.

Have just taken 2photos to confirm the issue. Don't know how to upload them to the Thad but it confirms Media Centre is displaying a very different picture to WMP. I went through the display setup again, changed nothing as it was all in order. Only affects DVD playback.

Very weird.