Macro blocking I see is on all channels regardless of signals. I even tried an indoor antenna directly to the unit and seen as well. Let me define what I see. The screen image will freeze for a moment then a portion of the image will kind of blur with little boxes of the image. Kind of like they're misplaced. These are not white blocks or green blocks that you see when the signal is weak. Sometimes this happens frequently (couple of minutes) or infrequently (1x per hour). Sometimes it's a small area, 10% of the screen, sometimes it's the whole screen. After a second, everything returns to normal. Happens on Live TV or recording, and if you play the recording again, in the exact same spot, so from the tuner.
On the upconverting issue, it's not all the time. For example, I recorded Hometime on PBS HD, it is 4x3 upconverted with black side bars. I turned on the unit and played, audio/video kept going off/on until I switched to 480i output, and then fine as long as I left 480i. I was watching another program a week later and noticed it was working fine on upconverted commercials. Played Hometime recording again and no problems with 1080i output.
Both these problems occur with firmware v1.3.8, v1.4.2, v1.5.4 and beta v1.6.8. Channels black no audio v1.4.2 and v1.6.8 only.
Another note, I popped out the tuner to reseat and notice the label is T431 not T411. I'm assuming a T411 and T431 are the same with a different program flashed.