HDMI Audio Dropout on Pace DVR

So, I've just had U-Verse installed, and as soon as the tech left, I noticed no audio.  Here's my configuration:

Pace IPH8005 DVR - HDMI out to Monoprice HDMI switch (along with several other components)

One optical audio out to Bose sound system.  ( Only have one optical audio available )

This configuration worked just fine for Comcast, but while I have great picture, the sound drops out in less than a second.  Everything works fine if I go directly from the DVR to my TV via HDMI, but not through the switch (which is working properly).  The temporary workaround I found is to run optical audio from my DVR to my Bose system, but this won't work, as that excludes all of my other devices.

I spoke with a pretty decent U-Verse tech guy, who is sending a new box out tomorrow.  He says, however, that there have been firmware updates which include DRM protections, which may be causing this lack of sound through HDMI. 

Also, there is no difference beteween selecting  "Stereo" and "Surround" in the system menu.

I see this was a fairly common problem a few years ago, but it appeared that it had been corrected.

Anyone having this issue?  Aware of a permanent fix?  Thanks!