I can't remember, what does the box "not" do with 131P, or is it you just want a clean box?
My receiver has the PVR issues with high bitrate video, but PVR works fine on stuff like PBS HD, and OTA HD, which is what I usually use it on. I've been told that the PVR worked OK with the factory firmware, but I can't verify that because my 9000 had 131p on it when I bought it from some guy in Ottawa who told me that it had original factory firmware.
My MAIN issue with the 131p is that I get periodic video freezes. They are very short freezes, and I've pretty much learned to ignore them, but they are constant. The period seems to vary with the bitrate of the video. Lower bitrate HD might freeze only every minute or two, but high bitrate video will freeze more frequently.
At one time, I thought I had found a way to stop the freezing, and another time, the freezing actually stopped for about a month or two, but it came back.
I emailed the Diamond people (when they still existed) and asked whether they could fix it (for a fee obviously), but got no reply. Now, the only hope is the hackers who caused the problem, however, it's possible that the cure might require more than just a firmware upgrade. Since one version firmware apparently does video and PVR properly, but no audio, and the 131p does audio properly, it seems like there should be some firmware solution, but perhaps not, or perhaps it's just that the only people capable of doing it aren't willing to do it for free, and the Diamond people aren't paying.
Yeah, I wish that whoever was doing the firmware for this thing would throw us a bone, because this is really a nice receiver otherwise.