In July of 2014 I posted the following to this forum.
"I have the SA 8240 HDC DVR running Rovi 3.7 with the Advanced TV package. The scenario: I'm watching a previously recorded program while also recording another program. What happens: When the program that is recording ends and stops recording, the previously recorded program that I am watching stops playing and reverts to live TV. I have to go into the DVR list, find it, select it and press resume playback. I haven't had this box for very long so I'm not sure if this is a normal operation. My old box never did this."
There were no replies from Cox or from anyone else addressing the particular problem. However, a short time later, it stopped doing that. I had and still have no idea as to why it did it or why it stopped. Although, I believe I do remember an intervening software update of some kind. There were some new features in the menu but the firmware version number did not change. Which was odd. Currently running Passport Echo 3.7.016 from Dec. 2013.
This is not behavior that I have ever experienced with my Rovi DVR. There is no setting or feature that I know of that would cause or control this behavior, either. When your DVR interrupts playback with the new recording, does the DVR display the DVR List menu, or does the new recording start playing right away?
As I wrote, mine stopped doing it, apparently on it's own, over two years ago. When it did, it would switch to show the scheduled recording immediately. No DVR list, no warning screen about two tuners in use.
The no warning screen, I thought at the time, was important because there was speculation in other quarters that it had to do with using both tuners while trying to watch a third show. But I kept stressing that I was watching a recorded show when it occurred. But that is probably the path where the answer lies.
After the box self-corrected I thought no more about it, so if I can, I'll make a flow chart and timeline to try and piece together what was happening at the time of the anomaly. Possibly test out variables in attempt to replicate as well.
Called Cox, after you folks confirmed this isn't normal, and they also said this was strange. So we reset the box and I'll take note of the exact time and circumstances if it occurs again. Thanks, everyone.
Wife also reports this happens only when programs from DisneyJR record, so we'll take good notes if this happens again.