An update to the information I posted yesterday. Again, Verizon FIOS in Tampa, new TiVo HD box, 2 Moto cablecards.
CC's were installed early in the morning. I watched TV most all day looking for the macroblocking issue. This included several movie channels for 20, 30, even 60 minutes at a time or more, and even a few analog channels in the lower set (2 through 49).
The entire time I watched yesterday until about 7pm, I had absolutely no macroblocking issues, unless they occured every time I blinked. Then suddenly, after 7-8pm, I was watching Return of the Jedi (think it was on Starz!) that I'd decided to record while I watched something else. Went back later and watched the recorded program, and sure as hell, there was an instance of macroblocking in the recorded program. Just for a split second. I reversed the movie to before the spot where it occured and played it again, but then it was gone. Continued watching the movie, and several more instances of macroblocking cropped up, but at random intervals - sometimes two within 1 minute, then sometimes not another one for 20 minutes later. Just like the pics I've seen of the issue, the blocking is sometimes on most of the screen, and sometimes only on the lower 1/3 of the screen.
I went back and forth between recorded programs and live TV the rest of the night and continued to notice the problem on both, at odd random intervals. Then, I finally saw the macroblocking occur on the TIVO MENU as well. This didn't happen constantly, but it did happen. Apparently the blocking isn't being recorded into the stream, because I can't make it reproduce itself at the same spot on recorded content.
Why the heck the problem waited all day to start I have NO idea. As I said, I didn't see it all day until the evening. And, my signal on all channels doesn't dip below 100%.
But now I can also confirm I have it too. Even though I know TiVo can't fix it (yet), is it going to do any good to call them and open a ticket on it?
Maybe we're actually dealing with more than one issue with the boxes. My Series 3 absolutely doesn't exhibit this behavior at all.