Comment 5 for bug 84900

btw:

as a workaround it is possible to build the alsa jack pcm plugin from source..

0] install libasound2-dev package
1] get the alsa-plugins tarball from http://www.alsa-project.org
2] extract the tarball somewhere
3] configure --prefix=/usr and make (you can even try make only in the jack subdir if the whole build fails)
4] manually copy the libasound_module_pcm_jack.la to /usr/lib/alsa-lib/
5] profit in the form of heightened enjoyment of ubuntu