Problems with sound?

I use the WDTV more or less just for movies… I rip the DVD to an external and play them using the WDTV.  I have not had any issues at all until I started ripping the Creature Comfort series.  Ripped them using AnyDVD (which I have always used with no problems) but these files don’t want to play.  Decided to use the ArcSoft converter software that came with the unit to convert the files so they will play… which they do… but without any sound.  Anybody had this issue or have a solution?