Could the encoders be programing to keep sending the DD5.1 signal even during the glitch times instead of just blanking?
I've seen glitches that I couldn't hear and it seems from reading here that some of these other AVRs are cycling on some of these extremely short glitches, thus causing the viewer to lose 1 to 2 sec of sound that wasn't that long of a glitch in the feed. If the feed could keep these locked onto the DD5.1, so the AVRs didn't cycle, it seems a fair amount of the dropouts might be reduced. Some dropouts don't seem to be real [in the feed but merely a loss of the Dolby bits] and others are longer but seem to be less than a second [to my ears on those I heard] so if the AVR didn't have to cycle then these would only be small dropouts.
VOS, you (and Stuart) may be onto something. When I turn my AVR on, or switch to, my AVR takes 1-3 second longer to come on than it does using other audio source materials. Since my dropouts while watching D* recorded material is 2-4 seconds, the differing one second may be that glitches. Also, the glitch could be one second, but with the AVR recovery/recycle time it might explain why I complain of 2-4 second gaps.