Every once in awhile I will go to watch a show that I recorded on my HDPVR (Motorola DCX3510-M). Under the list, the show says completed successful recording for the complete allotted time. However, when I watch the show, I get 20-30 minutes into it & then it stops & kicks me back to regular tv. I try to "resume" watching where it stopped but I cannot. Any idea what is causing this or how to fix this?