[Hardy] module-suspend-on-idle fails an assertion when manually configuring alsa outputs

I commented out "load-module module-hal-detect" and added in "load-module module-alsa-sink device=dmix" as well as "load-module module-alsa-source device=dsnoop", in an effort to get PulseAudio to use dmix so that Skype can coexist with it. However, occassionally, I get some assertion failed:
pulseaudio: pulsecore/source.c:273: pa_source_post: Assertion
 `PA_SOURCE_OPENED(s->thread_info.state)' failed.

This is very similar to the case reported here: https://tango.0pointer.de/pipermail/pulseaudio-discuss/2007-October/000800.html
Appropriate snippet:
Second, PulseAudio would crash on startup with this message:
I: module-suspend-on-idle.c: Source bluetooth.monitor idle for too long,
 suspending ...
pulseaudio: pulsecore/source.c:273: pa_source_post: Assertion
 `PA_SOURCE_OPENED(s->thread_info.state)' failed.
(In fact, nobody ever opened that source.) To cure the problem I omitted
loading module-suspend-on-idle, but it looks like a nice feature, and is
there something I might have done / not done to break it?

In my case, omitting module-suspend-on-idle also stops this from happening.

Also this problem happens randomly. Sometimes it works, sometimes it doesn't. As such I suspect it's some sort of race condition.

Backtrace when it does happen:
#0 0xb7f00410 in ?? () from /usr/lib/libsndfile.so.1
#1 0xb7705d58 in ?? ()
#2 0x00000006 in ?? ()
#3 0x00003e58 in ?? ()
#4 0xb7b8ff75 in ?? ()
#5 0xb7cafff4 in envz_merge () from /lib/tls/i686/cmov/libc.so.6
#6 0xb7b91a45 in ?? ()
#7 0x00000006 in ?? ()
#8 0xb7705d6c in ?? ()
#9 0x00000000 in ?? ()

Output of "pulseaudio -vv"
I: main.c: We're in the group 'pulse-rt', allowing real-time and high-priority scheduling.
I: core-util.c: Successfully gained nice level -11.
I: main.c: setrlimit(RLIMIT_NICE, (31, 31)) failed: Operation not permitted
I: main.c: setrlimit(RLIMIT_RTPRIO, (9, 9)) failed: Operation not permitted
I: main.c: Page size is 4096 bytes
I: main.c: Fresh high-resolution timers available! Bon appetit!
I: module-alsa-sink.c: Successfully opened device dmix.
I: module-alsa-sink.c: Successfully enabled mmap() mode.
ALSA lib control.c:909:(snd_ctl_open_noupdate) Invalid CTL dmix
I: alsa-util.c: Unable to attach to mixer dmix: No such file or directory
I: alsa-util.c: Unable to attach to mixer hw:(null): No such device
I: sink.c: Created sink 0 "output" with sample spec "s16le 2ch 48000Hz"
I: source.c: Created source 0 "output.monitor" with sample spec "s16le 2ch 48000Hz"
I: module-alsa-sink.c: Using 5 fragments of size 4096 bytes.
D: module-alsa-sink.c: Thread starting up
D: rtpoll.c: Acquired POSIX realtime signal SIGRTMIN+29
I: module-alsa-sink.c: Starting playback.
I: module.c: Loaded "module-alsa-sink" (index: #0; argument: "device=dmix sink_name=output").
I: module-alsa-source.c: Successfully opened device dsnoop.
I: module-alsa-source.c: Successfully enabled mmap() mode.
ALSA lib control.c:909:(snd_ctl_open_noupdate) Invalid CTL dsnoop
I: alsa-util.c: Unable to attach to mixer dsnoop: No such file or directory
I: alsa-util.c: Unable to attach to mixer hw:(null): No such device
I: source.c: Created source 1 "input" with sample spec "s16le 2ch 48000Hz"
I: module-alsa-source.c: Using 5 fragments of size 4096 bytes.
D: module-alsa-source.c: Thread starting up
D: rtpoll.c: Acquired POSIX realtime signal SIGRTMIN+28
I: module.c: Loaded "module-alsa-source" (index: #1; argument: "device=dsnoop source_name=input").
D: cli-command.c: Checking for existance of '/usr/lib/pulse-0.9/modules//module-hal-detect.so': success
I: module.c: Loaded "module-esound-protocol-unix" (index: #2; argument: "").
I: protocol-native.c: loading cookie from disk.
I: module.c: Loaded "module-native-protocol-unix" (index: #3; argument: "").
I: module.c: Loaded "module-volume-restore" (index: #4; argument: "").
D: module-default-device-restore.c: No previous default sink setting, ignoring.
D: module-default-device-restore.c: No previous default source setting, ignoring.
I: module.c: Loaded "module-default-device-restore" (index: #5; argument: "").
I: module.c: Loaded "module-rescue-streams" (index: #6; argument: "").
D: module-suspend-on-idle.c: Sink output becomes idle.
D: module-suspend-on-idle.c: Source output.monitor becomes idle.
D: module-suspend-on-idle.c: Source input becomes idle.
I: module.c: Loaded "module-suspend-on-idle" (index: #7; argument: "").
D: cli-command.c: Checking for existance of '/usr/lib/pulse-0.9/modules//module-x11-publish.so': failure
D: cli-command.c: Checking for existance of '/usr/lib/pulse-0.9/modules//module-gconf.so': success
D: module-gconf.c: Loading module 'module-native-protocol-tcp' with args '' due to GConf configuration.
I: protocol-native.c: using already loaded auth cookie.
I: protocol-native.c: using already loaded auth cookie.
I: module.c: Loaded "module-native-protocol-tcp" (index: #8; argument: "").
D: module-gconf.c: Loading module 'module-esound-protocol-tcp' with args '' due to GConf configuration.
I: module.c: Loaded "module-esound-protocol-tcp" (index: #9; argument: "").
D: module-gconf.c: Loading module 'module-zeroconf-publish' with args '' due to GConf configuration.
D: module-zeroconf-publish.c: Publishing services in Zeroconf
D: module-zeroconf-publish.c: Successfully created entry group for hyperair@Hyperair-PC: ALSA PCM on dmix (dmix) via DMA.
D: module-zeroconf-publish.c: Successfully created entry group for hyperair@Hyperair-PC: ALSA PCM on dsnoop (dsnoop) via DMA.
I: module.c: Loaded "module-zeroconf-publish" (index: #10; argument: "").
I: module.c: Loaded "module-gconf" (index: #11; argument: "").
I: main.c: Daemon startup complete.
I: module-zeroconf-publish.c: Successfully established service hyperair@Hyperair-PC: ALSA PCM on dmix (dmix) via DMA.
I: module-zeroconf-publish.c: Successfully established service hyperair@Hyperair-PC: ALSA PCM on dsnoop (dsnoop) via DMA.
I: module-zeroconf-publish.c: Successfully established main service.
I: module-suspend-on-idle.c: Source input idle for too long, suspending ...
I: module-alsa-source.c: Device suspended...
I: module-suspend-on-idle.c: Source output.monitor idle for too long, suspending ...
pulseaudio: pulsecore/source.c:278: pa_source_post: Assertion `PA_SOURCE_OPENED(s->thread_info.state)' failed.
Aborted