First of all thank you all for the wonderfull work.
I have allways a clicking noise (Speaker or Headphone) and in the logfile repeating entries:
01.05.09 10:07:59 kernel IOAudioStream[0x3985f00]::clipIfNecessary() - Error: attempting to clip to a position more than one buffer ahead of last clip position (191,2c9)->(192,45b).
01.05.09 10:07:59 kernel IOAudioStream[0x3985f00]::clipIfNecessary() - adjusting clipped position to (192,2c9)
Tried reducing volume but no change.
UPDATE: Version without Prefpane works fine.