There are two glitches occurring right now that maybe might explain some of it?
1. Overlap... The tivo software now tries to use one tuner when recording sequential shows on a channel, this causes two problems, that there is a glitch in the 2nd recording when the 1st one ends, and if the overlap is large some peeps have reported problems with missed recordings
2. If you manually adjust recording times of say, something scheduled to record via a season pass, It sometimes makes duplicate copies of recordings that have a screwed up name (that supposedly eventually fixes itself) that appear to be recording at the same time.
Both of these are scheduled to be fixed in the next update.
The other option is that your tivo was temporarily insane and the reboot straightened it out.
-Roamio Pro/Slide Pro
-Stream (Gotta go unplug the sucker one of these days!)