Cable companies push out firmware updates and bizarre things like this happen. It sounds like one unit is working so the best thing to do is to use that one with this cable box.
I don't expect things to get better in the industry because of all the copy protection built into HDMI (HDCP).
My ysp-4000 has suddenly interpeted my cable hdmi connection as dvi. The prior 18 months it identified the connection as hdmi. I have swapped cable boxes and hdmi cables, no fix. This misinterpetation I believe has caused a loss of sound for the cable connection. I have had cable service examined, Time Warner Cable, their feed is good. I have two ysp-4000's. I swapped them out and the problem is related to the specific ysp-4000. I have checked and double checked the settings on both ysp-4000's. Settings are the same. Both ysp's have no problem with their PS3 connections. What could be causing this sudden problem. These sound bars fit my needs perfectly. Any thoughts?