You're wandering way off the range by now, and as such I'm not sure what's going on.
With the CCK, you have both the Genie & HR24 being fed through a common point.
If they're acting the same, then this suggests "some normality".
A wildcard may be the OnDemand recording itself, so comparing others should help to weed out a bad OnDemand file on DirecTV's end.
i have an old HR20 that i haven't deactivated yet, maybe i'll hook that up tomorrow and give that a shot to see if it acts the same as the 24...