Squeezebox Internet radio 'sputtering?

I have installed a Logitech Squeezebox/Duet combo fed with Internet signal from the primary router via an Ethernet connection and running analog interconnects into my processor. My Internet speed is as high as it can get in residential applications (30Mbps downloads/2.5 Mbps uploads). Internet radio with 128 kbps stations has many drop outs and becomes inaudible when the music changes to speech/announcements. Classical stations are somewhat better than pop stations at the same signal rate of 128 kbps. Any idea what the problem might be?