Gstreamer and ALSA USB

Hi,

I have tested Gstreamer on a xM (Rev A2) under Angstrom with gstreamer-
properties and the audio and video tests work fine. However when I use
gst-launch, I get the following in the debug. What am is wrong with
the sink? I also have tried this in Exaile selecting ALSA, but it does
not find the sink.

results from - GST_DEBUG=3 gst-launch playbin uri="file:///usr/share/
sounds/alsa/Noise.wav":

WARN autodetect gstautoaudiosink.c:
370:gst_auto_audio_sink_detect:<audiosink> error: Failed to find a
supported audio sink
0:00:03.068939209 1769 0x25bcc8 INFO GST_ERROR_SYSTEM
gstelement.c:1761:gst_element_message_full:<audiosink> posting
message: Could not initialize supporting library.
0:00:03.069152832 1769 0x25bcc8 INFO GST_ERROR_SYSTEM
gstelement.c:1784:gst_element_message_full:<audiosink> posted error
message: Could not initialize supporting library.