This is driving me nuts!

[Mogwa]

After a restore of a system crash my, PC will play my video DVD (converted fom avi/xvid/mpeg/etc.) backups fine, but they will no longer function on my stand alone video player hooked up to the living room television.
I'm using the same media (Sony), recorder (HP 1040), at the same speed with the same codecs (cole 2k1 pack), and software (Winavi/Convertx to DVD/Ashampoo Burner Studio) that was previously installed and worked perfectly for many months. Yet whenever I insert a backup disc into the stand alone player that has always performed flawlessly, I always receive a "Disc error...playback features may not be available" message.
After a second complete re-install and experimenting with other burning proggies, the results are still the same.
If anyone has any solutions or suggestions, I'd really appreciate hearing from you. Thanks!