It sounds like your unit is set up and operating properly. If the 1070 reported a Dolby Digital 3/2.1 signal, that means it was seeing a 5.1 input: "3" being the front three channels, "2" being the two surrounds, and ".1" being the LFE. A Dolby 2.0 signal would be listed as 2/0.0.

It sounds to me like either a weak surround mix (not familiar with Sopranos to know what sort if mix it usually offers) or a screw up at the local cable company. I've had the local network affiliates screw up 5.1 soundtracks before (the worst case being when they took a 5.1 signal and made it 2.0 by throwing away everything except the left and right channels, leaving the resulting signal devoid of dialogue).