struggling with gnome-sound-recorder...

...and indeed rec and record also don't work. All three of these record nothing, and the text vu meter doesn't move in record - although I can play sound through the sound card.
gnome-sound-recorder gives the error message
Audio File Library: warning: opening file for read access: ignoring file setup with non-raw file format [error 23]
when I try to play or press stop after recording.

Can anybody suggest what is going wrong, or suggest some diagnostic test?

-Cheers
Colin