I might be stretching here, but is it possible that something went awry during production of the discs? Maybe the DTS surround mix is defective and not as intended, and something went wrong during coding...
Here me out. Now, I've never heard any other mixes from Mr. P-dub, so I have nothing to compare. But he was responsible for the Bjork mixes, which I've always known to be rather highly regarded here. And looking through the Bjork polls, they're all highly rated. Bjork's Vespertine alone has fifteen "10" scores, and eight "9s". The lowest rating for it is a five, which was mainly because this individual didn't like the music (and later says "I would change my score to a 9").
To quote Neil Wilkes on Bjork's Debut; Homogenic; and Vespertine, respectively:
Additionally, Adam said the Spooky Action 5.1 sounded good to him, and I've read nothing to indicate it's a poor mix, otherwise...
It would seem that P-dub is actually a rather talented surround engineer. What happened?