12" PB Combo Drive

I have a new 12" PB and although the combo drive plays a Video DVD , if I try to look at the DVD from the desktop itself I can see folders but no files showing in the folders.
The same occurs with a Data DVD


However I can see files on a CD and can write to a CD if I wish

Is this normal behaviour for the combo drive do I have a problem ?

OK problem solved.

As simple as making sure that the software that writes the DVD will make a DVD that is fully compatable with the combo drive.

Still rather strange as you can see no files on a home made Video DVD but the video will play . Would have thought that if incompatabvle the DVD would be totally incompatable