Please update to the latest bugfix release 0.121.3 or at least to 0.120.1, which is the minimum version required by audacious-plugins, which I'm trying to build for EPEL.
Maybe also enable celt and libsamplerate support?
Taking ownership of the EPEL-6 branch.
jack-audio-connection-kit-0.121.3-1.el6 has been submitted as an update for Fedora EPEL 6. https://admin.fedoraproject.org/updates/jack-audio-connection-kit-0.121.3-1.el6
Package jack-audio-connection-kit-0.121.3-1.el6: * should fix your issue, * was pushed to the Fedora EPEL 6 testing repository, * should be available at your local mirror within two days. Update it with: # su -c 'yum update --enablerepo=epel-testing jack-audio-connection-kit-0.121.3-1.el6' as soon as you are able to. Please go to the following url: https://admin.fedoraproject.org/updates/FEDORA-EPEL-2012-12954/jack-audio-connection-kit-0.121.3-1.el6 then log in and leave karma (feedback).
jack-audio-connection-kit-0.121.3-1.el6 has been pushed to the Fedora EPEL 6 stable repository. If problems still persist, please make note of it in this bug report.