just wanted to let installers know that atleast in the atlanta comcast system that the new M (multi-stream) cable cards do not work in the series 3 dvrs just the single stream cards work and of course it takes you taking 3-4 cards out just to get 2 too work if not more than that now if you run into the tivo HD-DVR the M cards work fine.
This is CABL.com posting #201217. Tiny Link: cabl.co/m0vB