Distorted sound, chosing input device

On an installation Linux ubuntu 11.10, onboard sound card and external inpout device (zoom h2) I have some problems:

  1. Ardour starts up the Audio engine, but in this case the playback sound will be distorted and pulsating. If I startup jack via qjackctl before the sound is o.k. Changing preferences (latency etc.) in Ardour or jack doesn’t help.
  2. In no case jack/Ardour connects the chosen input device (external zoom h2) no matter if I chose it via linux or in the jack preferences. If I disconnect ardour from jack. cancel jack and reconnect ardour, jack starts up again and it works perfectly. Is there any way to start up this configuration directly?

Strange situation: If I start JAMin first, this starts up Jack, and I start Ardour then, all works best. The right Input edevice is chosen, and the sound is o.k.? Not understandable.