In case this is still an issue for you, we had a similar problem. We have a SW5E switch with at least 2 or 3 Earmixes daisy-chained on each of the 4 channels (all running from our StudioLive Series III 32-channel mixer). Randomly, about once a week or so, all of the Earmixes on the same SW5E channel would drop out with no sound. One week it was one of the channels, another week it was another. The blue link status LED on the Earmixes that went out would turn green.
We flashed the firmware on the StudioLive, the SW5E, and all Earmixes to the latest January 24th firmware and so far we no longer see the problem. Seems like a good fix at this point. Hope this helps.