I can't play/view any files

I just received the WD TV Live HD and finished setting it up.  It seems to find my Iomega NAS drive okay.  However, when I go to view/play any file, I get the message “Unable to play the selected file.  Please refer to the user manual for a list of supported file formats.”

I am trying to play *.avi, *.m2ts, & *.mkv.  The pictures I want to view are .jpg.

Does anyone know what is going on?

For reasons unknown, after a few reboots, all files are now playing without problem.  Very happy.