I don't have any anti-virus software on any of the switches or routers, but also just carried out a simple test by connecting the MD600, 818 and macbook to the same single switch and disconnected the wifi. Same result. I did look at the logs but can't make much of them. I looked up some of it and according to the articles I found, this points to faults in the code. But I think that there may be something with my Macbook, even if it only crops up in combination with Sooloos...

I will now go and look what an upgrade for the software will cost me:-(

Rowland Model6/BPS6, Rowland Coherence II, Levinson 390S and 37, AudioAanZee Reference Flow music server, Rowland Aeris DAC, Rowland Cadence phono stage, Pass Labs Xono phono stage, Yamaha PX-2 and Thorens TD 160MKII, Transparent Ultra and Reference cables, Apogee Diva magnetostatics (refurbished).