WD TV Live Plus w/ WD hard drive. Movies disappear?

Have a WD TV Live Plus hooked to some WD external 2tb hard drives.  Each hard drive has several hundred movies on it.  Sometimes after the kids watch a movie a couple of times, it just disappears!!  They don’t have the expertise to go in and delete them, they just disappear.  When I hook the hard drive back to the computer, the folder that held the movie is still there, but instead of the movie and the picture of the cover that were in the folder, there is are suddenly two folders in the original folder.  One says it’s the movie and one says its the picture, but both are empty and not valid. 

Any ideas why movies will just disappear?  It happens quite often anymore.

Look at http://community.wd.com/t5/WD-TV-Live-Live-Plus/WDTV-Live-random-avi-files-being-converted-to-folders/td-p/544999

Sadly there is no fix except downgrading, which reveals other problems