Mystery solved. It's not your box, it's our upconversion.
On SD shows the DV is on track 3. When it's upconverted audio 3 is used for center channel, so the DV needs to be shuffled to audio 7+8 (second PID, Dolby Digital 2.0). Today's show was incorrectly upconverted, as was the show on the 7th. The proper people have been informed. Sorry for the confusion and thanks for the feedback.
CBC English Radio, TV and web streaming.