Hi!
I have already posted the same issue in the Madsonic forum here: http://forum.madsonic.org/viewtopic.php?f=18&t=1099&e=0, as it affects Madsonic for Android as well.
I don't know if you are familiar with the ViPER4Android app http://forum.xda-developers.com/showthread.php?t=2191223, it is an equalizer for Android, which improves the music quality tremendously. I have tried to get it working with DSub, but viper stops working a few seconds after DSub has been launched. When I close DSub, viper starts working again. Poweramp for instance has no problem with viper.
I was trying the Madsonic client for Android I found in their forum (Version 4.0.8 ), to see if it works with viper4android. (I have also tried Subsonic, and it did not work with viper either, so I gave Madsonic a shot)
Madsonic 4.0.8 worked fine with viper, but when I bought v5.5.210, viper stopped working.
I have tried everything suggested on xda to get it to work, but since other players are working, and the old version of Madsonic was also working, I came to the conclusion that there must have been changes in Madsonic. And maybe the same is happening to DSub as well. Maybe this information is helpful for you, and you can troubleshoot why viper is not working with DSub.
I have used DSub for a couple of months now, and I really love the app. But ever since I tried viper4android, I cannot live without it
I would really appreciate if you could look into this, or maybe you have already resolved this issue (couldn't find anything on the forum), I would be very thankful!
Cheers!