There is a show that I record which NBC has deliberately extended over the hour mark (It's a very highly rated show and so they want to prevent viewers from changing the channel... not a new technique). I also record the immediately following show (that they are trying to promote by this ploy). For various reasons, I watch the following show first, and I have noticed the last scenes of the preceding show at the beginning of the DVR recording.
So, I extended the timer of the preceding show by two minutes, and expected that the dual tuner would record them on two different tuners, and the preceding show would end up with 1:02 and the following show still have 1:00 (in case NBC stopped doing this).
But - I forgot that I was already using the second tuner for yet another show at the time - a low priority show that I often don't even watch.
So, what should have happened is that the low priority show should have not been recorded.
But what I discovered is that - with no warning at all - the 622 will throw away up to 3 minutes of overlap in order to avoid failing to record a show (regardless of the priorities).
The preceding show was recorded only for 1:00, is missing the last scenes, and so I have to be careful to not delete the following show, because that actually has my only copy of the ending of the preceding show (which I have not watched yet).
This is all rather complex, but the point is that AFAIK it is undocumented, there is no warning, and I end up with a low priority show being recorded instead of the ending of my high priority show.
I tested this, and if you add on 5 minutes or more, then it always records the added time, and dumps the lower priority recording.
No doubt, the theory is "If it is 5 minutes or more, then it is the overtime of a sports event, and we must record that. If it is 3 minutes or less, then it probably is just a casual just-in-case extra time, and the user probably would rather that we not fail to record a whole show just for that extra time."
So, the workaround is to always add at least 5 minutes if the extra time added is important.
So, I extended the timer of the preceding show by two minutes, and expected that the dual tuner would record them on two different tuners, and the preceding show would end up with 1:02 and the following show still have 1:00 (in case NBC stopped doing this).
But - I forgot that I was already using the second tuner for yet another show at the time - a low priority show that I often don't even watch.
So, what should have happened is that the low priority show should have not been recorded.
But what I discovered is that - with no warning at all - the 622 will throw away up to 3 minutes of overlap in order to avoid failing to record a show (regardless of the priorities).
The preceding show was recorded only for 1:00, is missing the last scenes, and so I have to be careful to not delete the following show, because that actually has my only copy of the ending of the preceding show (which I have not watched yet).
This is all rather complex, but the point is that AFAIK it is undocumented, there is no warning, and I end up with a low priority show being recorded instead of the ending of my high priority show.
I tested this, and if you add on 5 minutes or more, then it always records the added time, and dumps the lower priority recording.
No doubt, the theory is "If it is 5 minutes or more, then it is the overtime of a sports event, and we must record that. If it is 3 minutes or less, then it probably is just a casual just-in-case extra time, and the user probably would rather that we not fail to record a whole show just for that extra time."
So, the workaround is to always add at least 5 minutes if the extra time added is important.