Wow, this is a huge screw-up on NBC’s part. Lots of people are going to be upset when they don’t get the Olpympics coverage on their TiVo that they thought they were going to… (and thanks Dave, for the essay and link!)
Each of the channels showing the Olympics is using the same series name and their own, separate set of episode numbers. MSNBC has it’s episode 0, NBC has it’s episode 0, USA, etc… That means a wishlist for XXIX Summer Olympics is skipping episodes because it thinks it already recorded them. For instance, the Soccer game on MSNBC is keeping the opening ceremonies on NBC from recording. If you tell it to get all episodes, then you get lots of dups (like 4 of the opening ceremonies).
I don’t think this was actually an issue. No reports of this affecting anyone.