MP4 secondary audio not detected

I have some movies with secondary audio (English, Spanish) they reproduce I can select the audio fine in devices like iphone or reproducing using quicktime or vlc… WDTV Live will not detect it… Any guess on what should I change to have this functionality?

i have a few avis with dual audio tracks…

i press options on remote…then click the audio icon to toggle between the 2 audio tracks…