When I try to select a sound input using gstreamer-properties, I get an error.

Can you give some informations about your system?
Which version of Ubuntu do you run? What sound hardware do you have?

What happens when you do
gst-launch-0.10 audiotestsrc ! alsasink
gst-launch-0.10 audiotestsrc ! osssink

in a console?

I'm running an up-to-date Dapper system. I'm using an NVidia CK804. This was working before, it stopped working recently, I'm not sure when though.

Here are the command outputs:
shane@guXmeister:~$ gst-launch-0.10 audiotestsrc ! alsasink
Setting pipeline to PAUSED ...
Pipeline is PREROLLING ...
Pipeline is PREROLLED ...
Setting pipeline to PLAYING ...
New clock: audioclock0
Caught interrupt -- Pausing pipeline.
Pipeline paused.
WARNING: Element "pipeline0" warns: pipeline interrupted
Element "pipeline0" has gone from PLAYING to PAUSED, quitting.
Execution ended after 2325895000 ns.
Setting pipeline to PAUSED ...
Setting pipeline to READY ...
Setting pipeline to NULL ...
FREEING pipeline ...
shane@guXmeister:~$ gst-launch-0.10 audiotestsrc ! osssink
Setting pipeline to PAUSED ...
ERROR: Pipeline doesn't want to pause.
ERROR: from element /pipeline0/osssink0: Unable to open device /dev/dsp for writing: Device or resource busy
Additional debug info:
gstosssink.c(388): gst_oss_sink_open (): /pipeline0/osssink0
Setting pipeline to NULL ...
FREEING pipeline ...
shane@guXmeister:~$

Did the first one produce any audible output?

Yes, it did, then I did ^C, sorry for not explaining that.

oh sorry, we're talking of _input_ not output... my mistake

what happens when you do:
gst-launch-0.10 alsasrc ! fakesink

any errors?

shane@guXmeister:~$ gst-launch-0.10 alsasrc ! fakesink
Setting pipeline to PAUSED ...
Pipeline is live and does not need PREROLL ...
Setting pipeline to PLAYING ...
New clock: audioclock0
Caught interrupt -- Pausing pipeline.
Pipeline paused.
WARNING: Element "pipeline0" warns: pipeline interrupted

shane@guXmeister:~$

Nope, no errors or anything.

ok, i can confirm this bug here... attached are the output of 'GST_DEBUG=3 GST_DEBUG_NO_COLOR=1 gstreamer-properties'
it was killed at the moment where the error message popped up

alsasrc as input

osssrc as input

doing
gst-launch-0.10 alsasrc ! audioconvert ! audioresample ! alsasink

(which seems to be gstreamer-properties pipeline)

works fine

I reported this upstream: http://bugzilla.gnome.org/show_bug.cgi?id=336528

Seems to be fixed in feisty at least now... if someone can still reproduce it please reopen.

Reopening since I can reproduce it in gusty.

I'm attaching the output of 'GST_DEBUG=3 GST_DEBUG_NO_COLOR=1 gstreamer-properties' and choosing ALSA.
It was killed at the moment where the error message popped up.

I get the same error message for OSS. "Test Sound" and "Silence" work fine.

There is no clear indication that's the same issue could you open a new bug rather?

I've opened a new one: bug #144628.

I cant' choose between my Hauppauge TV card and my Logitech Quickcam MEssenger webcam : I get a segmentation fault.

Extract from my terminal (French Ubuntu) :

gstreamer-properties-Message: Skipping unavailable plugin 'artsdsink'
gstreamer-properties-Message: Skipping unavailable plugin 'esdsink'
gstreamer-properties-Message: Skipping unavailable plugin 'sdlvideosink'
gstreamer-properties-Message: Skipping unavailable plugin 'v4lmjpegsrc'
gstreamer-properties-Message: Skipping unavailable plugin 'qcamsrc'
gstreamer-properties-Message: Skipping unavailable plugin 'esdmon'
Erreur de segmentation