Here are three more that I did today. I chose random shows to record for the tests. I normally set the Save Until I Delete option and pad the shows at the beginning and end, although here I did pad the beginning mostly so I did not have to sit around waiting for the next half hour to start. The tuner numbers are the physical tuners as they are listed in the diagnostics. An easy way to see which is which is to turn off the box, when you power it back on it's on Tuner 1. I also occupied the alternate tuner so it would not change channels, although in my experience it doesn't always have to be occupied for the error.
Scheduled Recording on Tuner 1 for Andy Griffith Show, channel 163, Save until I delete, 11 minutes early.
Pressed Record on Tuner 2 for College Football on channel 4, record as planned when prompted for the Live Program notice, Continue and check space later on notification of 18% recording space left.
Watched channel 163, recording started as normal however College Football did not record due to cancellation by the system
Pressed Record on Tuner 2 for College Football on channel 4, record as planned when prompted for the Live Program notice, Continue and check space later on notification of 20% recording space left. Verified recording started this time.
Scheduled Recording on Tuner 1 for Andy Griffith Show, channel 163, Save until I delete, 9 minutes early.
Watched channel 163, show did not record, History shows due to fatal hardware error
Pressed Record on Tuner 1 for Andy Griffith Show, channel 163, verified recording started.
Scheduled Recording for Tuner 2 for Thomas & Friends, channel 118, Save until I delete, 12 minutes early.
Watched channel 118, show did not record, History shows due to fatal hardware error
My idea was it may have mattered which tuner it was, but it does not appear to be that way. There was also very little buffer on any test. My experience is that back to back shows (like Modern Family & Cougar Town) record most of the time, however I normally extend the recording of the first one to capture the second one too just in case. Even if there is another show in between I also extend to record that too just so I can guarantee that it doesn't have an error. Of course I have to make sure it's not on that channel to begin with
One last note, this was on my DCH model and not my DCX. I've had some of these issues since the old Microsoft guide and then A25 but it was not until A28 that I could actually see what the issue was. At least I am not going crazy wondering if I dreamed scheduling the shows in the first place any more.