Comment 5 for bug 829051

@Julian: the bugs you link to are very old. However they do contain clues as to what is happening and how to work around the bug (and it appears this is a recurrent problem with paprefs).

To bypass the bug, simply do:

sudo ln -s /usr/lib/pulse-0.99 /usr/lib/pulse-0.99.3

which is (according to strace) where paprefs was trying to locate the loadable modules. And according to the other bug reports, the fix is to rebuild paprefs along with the current pulseaudio, even though it does not directly link against it [!]. The Ubuntu packaging should change the dependencies accordingly so that this does not happen again.