Regardless whether I checkmark "System"-Mode in the Video Settings or "Elementary", the resulting file has just silence in the audio stream (if MPEG-1 audio is selected). Only when I select wav in Elementary mode there is sound. For most purposes I would want to have audio and video output in one file and for that mode there obviously is only the mpeg-1 option. Do I have to install some sort of MPEG-1 audio plugin for CCE?