jack says:
Cannot start jack server, please check the console or retry after a system reboot.
way to the solution:
after installing jack 0.90 from http://jackaudio.org/downloads/
jack always gave me an error message and did not start
reading of problems with user rights on the web i started jackpilot from the terminal as sudo
cd /Applications/Jack/JackPilot.app/Contents/MacOS
sudo ./JackPilot
this worked. jack started. now it’s time to change the user rights permanently with the solution on http://mixbus.harrisonconsoles.com/forum/thread-357.html
sudo chmod 0755 /usr/local/lib
sudo chmod 0755 /usr/local/bin
sudo chmod 0755 /usr/local/lib/jackmp
problem solved.
and yes, as mentioned in the harrisonconsoles article, i had an old version of audacity installed. i immediately updated audacity and ffmpeg/lame after this procedure.