TiVo chimed in on the TiVo HD macroblocking issue publicly last night, in the form of a TiVoCommunity.com post from TiVoPony:
Hey guys,
We are aware that some of you are still reporting macroblocking or pixelation on certain channels. The team here continues to gather information to understand possible causes – they’re making good headway.
The update we released on August 1st has proven to fix the issue for some customers, and we are working hard on a fix for the remaining cases. We will provide more concrete information as we can.
In the meantime, we appreciate your patience and the detailed feedback you’ve been providing.
Pony
It is nice to see them addressing the issue publicly, and re-affirming that they’re actively working on a fix.