I get garble DD 5.1 audio frequently from my two HR24-100s. I thought the source of the garble was my old Denon AVR in the living room. Recently, I noticed bad audio in the master bedroom which has a two year old Sony AVR. The Denon connects to the HR24 via a coaxial cable, and the Sony AVR connects with an HDMI cable. In my case, garbled audio comes from live and recorded video. I would blame the bad audio on signal strength, but the Slim5 was adjusted when SWim / DECA wireless was installed for MRV. My thought is this garbled audio relates to the SD / HD DD 5.1 issues.
Best wishes!