I'm not an Ubuntu user, I use Sidux and came accross this page by accident, but as they are both Debian and the symptoms are the same this might work for a temporary fix:
sudo lsof | grep /dev/snd
This should just list artsd. Kill it and run your sound app straight after.
Once your program has exited artsd is restarted and your program won't have sound again.
I know this isn't the answer but, if it does on Ubuntu what it does for my Sidux then, maybe somebody with a bit more knowledge can do something with it.
I'm not an Ubuntu user, I use Sidux and came accross this page by accident, but as they are both Debian and the symptoms are the same this might work for a temporary fix:
sudo lsof | grep /dev/snd
This should just list artsd. Kill it and run your sound app straight after.
Once your program has exited artsd is restarted and your program won't have sound again.
I know this isn't the answer but, if it does on Ubuntu what it does for my Sidux then, maybe somebody with a bit more knowledge can do something with it.