alsa Unable to set hw params for playback

Hello,

when I try to set ALSA in gnome-sound-properties I get this errormsg:
"audiotestsrc wave=sine freq=512 ! audioconvert ! audioresample ! gconfaudiosink:
Couldn't read/set from resource"

I can listen to sound when I tell it to automatically chosse, or use pulse-audio.

This is part of the debug-salad:

GST_EVENT gstevent.c:557:gst_event_new_new_segment_full: creating newsegment update 0, rate 1,000000, format GST_FORMAT_TIME, start 0:00:00.000000000, stop 99:99:99.999999999, position 0:00:00.000000000
0:00:12.185734735 7969 0x94c2ae0 INFO audioconvert audioconvert.c:459:audio_convert_prepare_context: use int mixing
0:00:12.185759576 7969 0x94c2ae0 INFO audioconvert audioconvert.c:465:audio_convert_prepare_context: unitsizes: 8 -> 4
0:00:12.185768588 7969 0x94c2ae0 INFO audioconvert audioconvert.c:475:audio_convert_prepare_context: in default 0, mix passthrough 1, out default 1
0:00:12.185801486 7969 0x94c2ae0 INFO audioconvert gstaudioconvert.c:394:gst_audio_convert_get_unit_size:<audioconvert0> unit_size = 8
0:00:12.185818928 7969 0x94c2ae0 INFO audioconvert gstaudioconvert.c:394:gst_audio_convert_get_unit_size:<audioconvert0> unit_size = 4
0:00:12.187248302 7969 0x94c2ae0 WARN alsa pcm_pulse.c:696:pulse_hw_params: alsalib error: PulseAudio: Unsupported format S32_LE

0:00:12.187281533 7969 0x94c2ae0 WARN alsa gstalsasink.c:528:set_hwparams:<alsasink0> error: Unable to set hw params for playback: Invalid argument
0:00:12.187313900 7969 0x94c2ae0 INFO GST_ERROR_SYSTEM gstelement.c:1677:gst_element_message_full:<alsasink0> posting message: Konnte die Einstellungen nicht aus der Ressource lesen oder in die Ressource schreiben.
0:00:12.187340787 7969 0x94c2ae0 INFO GST_ERROR_SYSTEM gstelement.c:1700:gst_element_message_full:<alsasink0> posted error message: Konnte die Einstellungen nicht aus der Ressource lesen oder in die Ressource schreiben.
0:00:12.187356069 7969 0x94c2ae0 WARN alsa gstalsasink.c:771:gst_alsasink_prepare:<alsasink0> error: Setting of hwparams failed: Invalid argument

I am not sure, but I think it happens, since i tried to install the ekiga 3.0 deb packages, (ptlib and stuff...)

lsb_release -rd:
Description: Ubuntu intrepid (development branch)
Release: 8.10