[LAU] could not start jack - already registered problem

Hello, I run KXStudio on Ubuntu 12.10 on a Lenovo Ideapad with a MAudio Mobile Pre USB1 interface. Normaly all this works near perfection but there is a problem starting Jack: Tue Apr 23 09:58:52 2013: Starting jack server... Tue Apr 23 09:58:52 2013: JACK server starting in realtime mode with priority 10 Tue Apr 23 09:58:52 2013: ERROR: cannot register object path "/org/freedesktop/ReserveDevice1/Audio2": A handler is already registered for /org/freedesktop/ReserveDevice1/Audio2 Tue Apr 23 09:58:52 2013: ERROR: Failed to acquire device name : Audio2 error : A handler is already registered for /org/freedesktop/ReserveDevice1/Audio2 Tue Apr 23 09:58:52 2013: ERROR: Audio device hw:MobilePre,0 cannot be acquired... Tue Apr 23 09:58:52 2013: ERROR: Cannot initialize driver Tue Apr 23 09:58:52 2013: ERROR: JackServer::Open failed with -1 Tue Apr 23 09:58:52 2013: ERROR: Failed to open server I then have to unplug the Mobile Pre, replug it and try again. After 3-4 tries it uses to work so the issue is no show-stopper for me but it is indeed most annoying. To be perfectly honest the only thing I really dearly would like to know is: Tue Apr 23 09:58:52 2013: ERROR: cannot register object path "/org/freedesktop/ReserveDevice1/Audio2": A handler is already registered for /org/freedesktop/ReserveDevice1/Audio2 What mechanism has registered the Audio-device, how does that prevent jack from starting and how can I end this for good? best regards HZN