This is possibly for cemsaral57:
I have two Soundbridges--one in my study and one in the kitchen. I use them for streaming radio. Until recently they worked perfectly--one at a time as well as both on. I went away for three days. Upon return, I encountered the constant rebuffering problem you describe with your deviceS (plural is important here). Unplugging and replugging the power supplies did not solve the problem. Individually, the configurations looked fine. I checked the devices in my browser but could see only one, and I could find only one when checking network devices on one of my computers. Furthermore, the identity was unstable when I looked at the device's properties. First it was the kitchen Soundbridge and then it was the Study Soundbridge. Eventually it dawned on me that both devices had the same dynamically assigned IP address. I unplugged the cable modem, router, and main switch for my home network. After replugging, I brought the devices up one at a time, checked that the dynamically assigned IP addresses were distinct, and noted that the rebuffering problem had disappeared.
I realize there are many, many possible sources of problems, but I hope this tale is helpful to at least some readers.