On a fresh, vanilla Lucid install I enabled the lucid-proposed repository, refreshed my sources, and installed ardour 1:2.8.6-1ubuntu0.1.
After adding myself to the audio group and rebooting I was able to start JACK via qjackctl and then Ardour. The Ardour tracks were muted as expected and desired.
Martin,
On a fresh, vanilla Lucid install I enabled the lucid-proposed repository, refreshed my sources, and installed ardour 1:2.8.6-1ubuntu0.1.
After adding myself to the audio group and rebooting I was able to start JACK via qjackctl and then Ardour. The Ardour tracks were muted as expected and desired.
Good job!