This happens shortly after running the daemon on the command line,
and it makes the daemon die:

core.h: Assertion 'pa_object_refcnt(pa_object_cast(o)) > 0' failed at ./pulsecore/core.h:159, function pa_core_assert_ref(). Aborting.

The following modules are installed:

bernie@bender:~$ rpm -qa | grep ^pulseaudio | sort
pulseaudio-0.9.15-3.test3.fc11.x86_64
pulseaudio-libs-0.9.15-3.test3.fc11.x86_64
pulseaudio-libs-devel-0.9.15-3.test3.fc11.x86_64
pulseaudio-libs-glib2-0.9.15-3.test3.fc11.x86_64
pulseaudio-libs-zeroconf-0.9.15-3.test3.fc11.x86_64
pulseaudio-module-bluetooth-0.9.15-3.test3.fc11.x86_64
pulseaudio-module-gconf-0.9.15-3.test3.fc11.x86_64
pulseaudio-module-x11-0.9.15-3.test3.fc11.x86_64
pulseaudio-module-zeroconf-0.9.15-3.test3.fc11.x86_64
pulseaudio-utils-0.9.15-3.test3.fc11.x86_64

Contents of /var/log/messages:

Mar  2 21:37:19 bender pulseaudio[29681]: main.c: Called SUID root and real-time and/or high-priority scheduling was requested in the configuration. However, we lack the necessary privileges:
Mar  2 21:37:19 bender pulseaudio[29681]: main.c: We are not in group 'pulse-rt', PolicyKit refuse to grant us the requested privileges and we have no increase RLIMIT_NICE/RLIMIT_RTPRIO resource limits.
Mar  2 21:37:19 bender pulseaudio[29681]: main.c: For enabling real-time/high-priority scheduling please acquire the appropriate PolicyKit privileges, or become a member of 'pulse-rt', or increase the RLIMIT_NICE/RLIMIT_RTPRIO resource limits for this user. 
Mar  2 21:37:19 bender pulseaudio[29684]: pid.c: Stale PID file, overwriting.
Mar  2 21:37:19 bender pulseaudio[29684]: alsa-util.c: Cannot find fallback mixer control "Mic" or mixer control is no combination of switch/volume.
Mar  2 21:37:22 bender pulseaudio[29684]: alsa-source.c: Increasing minimal latency to 8.00 ms
Mar  2 21:37:22 bender pulseaudio[29684]: alsa-source.c: Increasing minimal latency to 8.00 ms
Mar  2 21:37:22 bender pulseaudio[29684]: alsa-source.c: Increasing minimal latency to 16.00 ms
Mar  2 21:37:22 bender pulseaudio[29684]: alsa-sink.c: Increasing minimal latency to 8.00 ms
Mar  2 21:37:22 bender pulseaudio[29684]: alsa-sink.c: ALSA woke us up to write new data to the device, but there was actually nothing to write!
Mar  2 21:37:22 bender pulseaudio[29684]: alsa-sink.c: Most likely this is a bug in the ALSA driver 'snd_hda_intel'. Please report this issue to the ALSA developers.
Mar  2 21:37:22 bender pulseaudio[29684]: alsa-sink.c: We were woken up with POLLOUT set -- however a subsequent snd_pcm_avail() returned 0 or another value < min_avail.
Mar  2 21:37:22 bender pulseaudio[29684]: alsa-source.c: Increasing minimal latency to 26.00 ms
Mar  2 21:37:22 bender pulseaudio[29684]: alsa-source.c: Increasing wakeup watermark to 15.99 ms
Mar  2 21:37:22 bender pulseaudio[29684]: alsa-source.c: Increasing minimal latency to 36.00 ms
Mar  2 21:37:22 bender pulseaudio[29684]: alsa-source.c: Increasing wakeup watermark to 25.99 ms
Mar  2 21:37:22 bender pulseaudio[29684]: alsa-source.c: Increasing minimal latency to 16.00 ms
Mar  2 21:37:22 bender pulseaudio[29684]: alsa-sink.c: Increasing minimal latency to 16.00 ms
Mar  2 21:37:28 bender pulseaudio[29684]: ratelimit.c: 129 events suppressed
Mar  2 21:37:28 bender pulseaudio[29684]: alsa-source.c: Increasing minimal latency to 26.00 ms
Mar  2 21:37:43 bender pulseaudio[29684]: core.h: Assertion 'pa_object_refcnt(pa_object_cast(o)) > 0' failed at ./pulsecore/core.h:159, function pa_core_assert_ref(). Aborting.