DVR Recordings Freeze

Our Contour DVR freezes when playing back a recorded program.  We have reset the box multiple times and checked he connections and it still freezes and will not allow the rest of the show (even though it shows it fully recorded) to be played.  It does not do it with all shows and is not specific to any particular set of shows, it is random.  Trying to use one of the other non-dvr boxes for play back results in the same issue.  Do we need to replace the box?