Decided to rebuild my Ubuntu Server. PInstalled Twonky 7.2.8. Unfortunately I have the problem (as I had several times before with former Twonky versions) that tracks are listed alphabetically and not in track order. With former Twonky versions I was able to solve this matter, now I am not. I added the extra lines to view-definitions.xml, but that does not help.
It is a problem with the Denon AVR3808. When I use another device (Dune HDmax) the tracks are in the proper order.
With older versions of Twonky it could be solved by adding XM:IGNORESORT to clients.db, where you directly influence the specific media player (i.e. the Denon). But this possibility seems to be gone with this Twonky version.