Recording scheduling anomalies

I've had my basic Roamio for about a month, and sometimes its recording scheduling with season passes & straight recordings mess-up in a way that my previous Series2 never did. It seems to occur at least mostly when shows are set to record longer, such as for delayed Sunday night CBS shows, and the shows are overlapping. For example, my problem occurred last night when I had season passes for over-the-air broadcasts of The Good Wife and The Mentalist both set to record 30 minutes longer, but The Mentalist never recorded. I observed The Mentalist in my To Do list just sitting there not recording after its time to begin (10:00 PM, wrong-in-retrospect). Later, while The Good Wife was still running, The Mentalist just disappeared from my To Do list. My History said it no longer was in my Program Guide, but it *was* still in my Program Guide when I inspected it. So then I hit the Record button from within my Program Guide and it appeared in my To Do list, but never began recording, and again just sat there after its scheduled time (and even after its actual delayed time). I don't understand this weird behavior when I have four tuners: Shouldn't Good Wife & Mentalist have been recorded on separate tuners at their scheduled-but-wrong times?... Other times — and these involve unscheduled delayed shows, too — the next morning I've greeted David Letterman not recorded, but Now Playing shows a couple of recordings of only a few minutes length that are unnamed with only the time of night displayed in the title. (I know my power didn't go out because my microwave oven clock was still correct, and besides, I've seen TiVo History actually say the power had gone out before.) Has this kind of thing ever happened to you?