If MC actually does record repeats of programs even after the first or subsequent airings have been successfully recorded, then there are a few possibilities as to why;
1. As Yaobing reminded me, if the duration of the first recording is less than a later recording, MC will record the second version. The assumption being that something was missed on the first recording, so it would be incomplete, and hence, not a successful recording. I don't usually see this issue though.
2. The EPG data is different for the first and subsequent recordings. I see this all the time, where most often the description changes on subsequent recordings, but also often the episode name is dropped and only the Series name is given, or perhaps only the episode name is given. MC relies on the EPG data. That's all it can do. As my EPG data isn't very reliable, I use "Series" name and "Episode" name to decide if a program is a repeat, which means I sometimes get duplicates.
With the programs you highlighted in the first image, and using Series Name and Description to determine if later airings are repeats, MC should do the correct thing and only record the first airing.
3. The EPG data has changed between the first and later airings. If that happens then your rule could fail, and a later airing will be recorded. Check the EPG data after the first recording, if the later airings are still selected to be recorded.
To be honest though, I haven't checked all the logic for a while, so something may have changed or been broken. But as you say it has been happening for years, if later airing are being recorded there must be some reason.
From a user perspective it would be nice if only the first airing of a program was shown in the "To be recorded" list, and if it didn't work a later airing would be added. Yaobing may have been able to code the software that way. But from memory then the second of back to back repeats would get missed, if the first failed. MC checks what needs to be recorded pretty regularly, but it doesn't do it constantly. If it did it would be loading the PC all the time, which would be bad.
Recordings can fail because an HTPC didn't wake or was locked up, or power failures, or there were no tuners available, etc. Usually things out of MCs control. So we, as users, want to make sure that a following airing gets picked up. The current software design does the best job at doing that, with the minor inconvenience that multiple airings of one program show up in the "To be recorded" list, until a successful recording is made.
P.S. What about the episodes it just ignores for no apparent reason?
Do you mean different episode from an episode already recorded? I don't get that. If it is happening, there is a difference in the EPG data that the Recording Rules don't take into account. I've seen stuff like "CSI" sometimes being listed as "C.S.I." and similar. A full stop or colon at the end of the Series Name, when I am doing an exact match. But if my rules are good, and the EPG has the data, MC picks it up as to be recorded.
