DVR Recorded limit lowered?

Today out of no where, all my shows were deleted (around 20) in my DVR even though I had about 62% full and when a new show was being recorded it said I no more space available, even though the dvr says 0 shows recorded and 0% full. Ten minutes later it starts to record the show with the percentage going up with the number of minutes that have been recorded. i.e 14 minutes = 14% full, before one show 30 min show would be around 5%. Did Cox cable shorten how much i can record or is the box faulty? I have power cycled the box but no resolution, please help