MPEG1 playback problems

[GoochyB]

I've got a bizarre problem playing back MPEG1 files. When I play them in Windows Media Player (v9) (or any other app.) the bottom third of the image is cut off and the top two thirds stretched to fill the playback window. The full width is shown.

This has started happening recently, and I've not installed anything recently which I can think would have caused it to change. I originally thought it was a problem with how the capture card was encoding the files, but have subsequently realised that it affects files which previously played normally and therefore it is the playback not recording that is at error. MPEG2 files are unaffected.

I've tried reinstalling WMP 9 to see if this would correct what I guess to be a codec error but it's not made any difference. Because of the delay in identifying the true problem there's no longer a Windows System Restore point that goes back to a time when the files were playing normally.

MPEG1 playback and codec are an integral part of Windows (I'm running ME) so I don't see how it can have been changed, and more importantly how to replace the codec if that is the problem.

Does anyone have ideas about what may be the problem and, if it is the MPEG1 codec, how to replace it with a working version. I obviously don't want to reinstall Windows if I can at all help it!

[petesimon]

Hmm...this is very interesting. Can you make a capture of your windows screen while this problem is happening and attach the file to your next post (use the "Upload image" feature)? I'd like to see it.

[GoochyB]

I've now solved the problem - I discovered it was also affecting AVI's, and that it only happened when they were viewed at other than 100%. It turned out to be something wrong with the installation of the graphics card driver that I'd updated last month. I re-ran the installer and the problem has now gone.