[Discuss-gnuradio] ALSA audio source not working---why?

[Henry Gernhardt III]

Folks---

I just successfuly compiled GnuRadio and its dependencies.  (YAY!!)  I have, 
however, run into a slight snag with audio.source().  When running anything 
using this little gem, I get the following (example output from 
spectrum_inversion.py):

audio_alsa_source[hw:0,0]: set_channels failed: Invalid argument
Traceback (most recent call last):
 File "spectrum_inversion.py", line 37, in ?
   main ()
 File "spectrum_inversion.py", line 32, in main
   fg.start ()
 File 
"/home/henry/gnuradio/lib/python2.4/site-packages/gnuradio/gr/flow_graph.py", 
line 69, in start
   self._setup_connections ()
 File 
"/home/henry/gnuradio/lib/python2.4/site-packages/gnuradio/gr/flow_graph.py", 
line 98, in _setup_connections
   self.validate ()
 File 
"/home/henry/gnuradio/lib/python2.4/site-packages/gnuradio/gr/basic_flow_graph.py", 
line 164, in validate
   raise ValueError, ("%s::check_topology (%d, %d) failed" % (m, ninputs, 
noutputs))
ValueError: <gr_block audio_alsa_source (0)>::check_topology (0, 1) failed

Any ideas as to what may be causing this?

TIA,

       Henry C. Gernhardt, III
       KE4PIB