Ok, so it appears that module-device-restore is attempting to use a
nonexistent sink/source, so it falls back to dummy/null. This is caused
by module-udev-detect not having loaded by the time module-device-
restore is loaded, as can be seen in /etc/pulse/default.pa (I'm
including the snippet from the source):
### Automatically restore the volume of streams and devices
load-module module-device-restore
load-module module-stream-restore
load-module module-card-restore
...
### Automatically load driver modules depending on the hardware available
.ifexists module-udev-det...@pa_soext@
load-module module-udev-detect
.else
### Alternatively use the static hardware detection module (for systems that
### lack udev support)
load-module module-detect
.endif
>From your log:
Apr 7 17:29:14 ubuntu pulseaudio[4049]: module-device-restore.c: Sucessfully
opened database file
'/home/ubuntu/.pulse/edb88c50b54cfd6a9837a2474bbca403-device-volumes'.
Apr 7 17:29:14 ubuntu pulseaudio[4049]: module.c: Loaded
"module-device-restore" (index: #0; argument: "").
Apr 7 17:29:14 ubuntu pulseaudio[4049]: module-stream-restore.c: Sucessfully
opened database file
'/home/ubuntu/.pulse/edb88c50b54cfd6a9837a2474bbca403-stream-volumes'.
Apr 7 17:29:14 ubuntu pulseaudio[4049]: module.c: Loaded
"module-stream-restore" (index: #1; argument: "").
Apr 7 17:29:14 ubuntu pulseaudio[4049]: module-card-restore.c: Sucessfully
opened database file
'/home/ubuntu/.pulse/edb88c50b54cfd6a9837a2474bbca403-card-database'.
Apr 7 17:29:14 ubuntu pulseaudio[4049]: module.c: Loaded "module-card-restore"
(index: #2; argument: "").
Apr 7 17:29:14 ubuntu pulseaudio[4049]: module.c: Loaded
"module-augment-properties" (index: #3; argument: "").
Apr 7 17:29:14 ubuntu pulseaudio[4049]: module-udev-detect.c: Found 1 cards.
Apr 7 17:29:14 ubuntu pulseaudio[4049]: module.c: Loaded "module-udev-detect"
(index: #4; argument: "").
Apr 7 17:29:14 ubuntu pulseaudio[4049]: module.c: Loaded
"module-bluetooth-discover" (index: #5; argument: "").
Apr 7 17:29:14 ubuntu pulseaudio[4049]: module.c: Loaded
"module-esound-protocol-unix" (index: #6; argument: "").
Apr 7 17:29:14 ubuntu pulseaudio[4049]: module.c: Loaded
"module-native-protocol-unix" (index: #7; argument: "").
Apr 7 17:29:14 ubuntu pulseaudio[4049]: module.c: Loaded "module-gconf"
(index: #8; argument: "").
Apr 7 17:29:14 ubuntu pulseaudio[4049]: module-default-device-restore.c: Saved
default sink 'alsa_output.usb-041e_USB_Audio-00-MP3.analog-stereo' not
existant, not restoring default sink setting.
Apr 7 17:29:14 ubuntu pulseaudio[4049]: module-default-device-restore.c: Saved
default source 'alsa_input.usb-041e_USB_Audio-00-MP3.analog-stereo' not
existant, not restoring default source setting.
Apr 7 17:29:14 ubuntu pulseaudio[4049]: module.c: Loaded
"module-default-device-restore" (index: #9; argument: "").
Apr 7 17:29:14 ubuntu pulseaudio[4049]: module.c: Loaded
"module-rescue-streams" (index: #10; argument: "").
Apr 7 17:29:14 ubuntu pulseaudio[4049]: module-device-restore.c: Restoring
volume for sink auto_null.
Apr 7 17:29:14 ubuntu pulseaudio[4049]: module-device-restore.c: Restoring
mute state for sink auto_null.
Apr 7 17:29:14 ubuntu pulseaudio[4049]: sink.c: Created sink 0 "auto_null"
with sample spec s16le 2ch 44100Hz and channel map front-left,front-right
Apr 7 17:29:14 ubuntu pulseaudio[4049]: sink.c: device.description =
"Dummy Output"
Apr 7 17:29:14 ubuntu pulseaudio[4049]: sink.c: device.class = "abstract"
Apr 7 17:29:14 ubuntu pulseaudio[4049]: sink.c: device.icon_name =
"audio-card"
Apr 7 17:29:14 ubuntu pulseaudio[4049]: source.c: Created source 0
"auto_null.monitor" with sample spec s16le 2ch 44100Hz and channel map
front-left,front-right
Apr 7 17:29:14 ubuntu pulseaudio[4049]: source.c: device.description =
"Monitor of Dummy Output"
Apr 7 17:29:14 ubuntu pulseaudio[4049]: source.c: device.class = "monitor"
Apr 7 17:29:14 ubuntu pulseaudio[4049]: source.c: device.icon_name =
"audio-input-microphone"
Apr 7 17:29:14 ubuntu pulseaudio[4049]: module.c: Loaded "module-null-sink"
(index: #11; argument: "sink_name=auto_null
sink_properties='device.description="Dummy Output"'").
Apr 7 17:29:14 ubuntu pulseaudio[4049]: module.c: Loaded "module-always-sink"
(index: #12; argument: "").
Apr 7 17:29:14 ubuntu pulseaudio[4049]: module.c: Loaded
"module-intended-roles" (index: #13; argument: "").
Apr 7 17:29:14 ubuntu pulseaudio[4049]: module.c: Loaded
"module-suspend-on-idle" (index: #14; argument: "").
Apr 7 17:29:14 ubuntu pulseaudio[4049]: client.c: Created 0 "ConsoleKit
Session /org/freedesktop/ConsoleKit/Session1"
Apr 7 17:29:14 ubuntu pulseaudio[4049]: client.c: Created 1 "ConsoleKit
Session /org/freedesktop/ConsoleKit/Session2"
Apr 7 17:29:14 ubuntu pulseaudio[4049]: client.c: Created 2 "ConsoleKit
Session /org/freedesktop/ConsoleKit/Session3"
Apr 7 17:29:14 ubuntu pulseaudio[4049]: client.c: Created 3 "ConsoleKit
