Nero 8 Burned MP3 nor playing in some devices!

When mp3 files were burned with 7 I could play them in all my devices. The files burned with 8 will play on my computer, my DVD/CD player connected to my media center, but not on any of my car players whuch played all mp3 disc created with Nero 7!

The same disc appear to play fine with the track and counter advancing normally but no sound! It is really weird and I would appreciate any help I can get.

Thanks