python alsa problems on BeagleBoard xm (Angstrom)

Dear all,

I am a beginner with BeagleBoard (xM) and audio. I am using Angstrom.
I've been investigating this issue without success and I have a kind
of feeling that I am missing something basic.

I am trying to use alsa audio from a python script.
The sample script provided with alsa audio package works on PC, but
not on BeagleBoard.
In the BeagleBoard the audio comes out just as noise.

I thought it would be wrong settings, but then I played the audio from

root@beagleboard:~# aplay -t wav -c 2 -r 44100 -f S16_LE -v
pyNewsPrint/audio/song01.wav

and the output provides me the same parameters I am using. (At least
these I am configuring).

Any idea?

this is the output of 'aplay' (working):

Playing WAVE 'pyNewsPrint/audio/song01.wav' : Signed 16 bit Little
Endian, Rate 44100 Hz,o
Plug PCM: Hardware PCM card 0 'omap3beagle' device 0 subdevice 0
Its setup is:
  stream : PLAYBACK
  access : RW_INTERLEAVED
  format : S16_LE
  subformat : STD
  channels : 2
  rate : 44100
  exact rate : 44100 (44100/1)
  msbits : 16
  buffer_size : 22016
  period_size : 512
  period_time : 11609
  tstamp_mode : NONE
  period_step : 1
  avail_min : 512
  period_event : 0
  start_threshold : 22016
  stop_threshold : 22016
  silence_threshold: 0
  silence_size : 0
  boundary : 1442840576
  appl_ptr : 0
  hw_ptr : 0