Thanks Tim

Well I'm getting 0% packet loss on all tests, but when I get the audio glitches, it's at times when the ping time spikes occasionally above 15-20ms. Most of the time the ping time is around 4ms, during which time the sound is just fine as you'd expect.

The servers upstairs are connected through an ethernet powerline extender, so I guess that might be a culprit for the occasional long round trips. The Mac Mini does nothing else but act as a music server, so there shouldn't be any problem there. I can only otherwise assume there's other network traffic causing some occasional congestion.

BTW what's your recommended MPD buffer settings (I can't remember what the original settings were)

Rob