Performous crash : Exception from playback callback

I wanna play Performous on my PC but it crashes.
The hardware/software configuration is the following :
 - processor intel atom
 - RAM : 1 GHz
 - using compiz
 - ubuntu 9.04 jaunty

The problem is the following :
I can launch correctly Performous software
The sound in the main menu page doesn't function
The menu function correctly
When I type 'P' practice mode is launching and Performous reconize the voice
When I type 'Q' or 'C', it is functionning well

/!\ BUT WHEN I type 'S', it crashes : black screen and processus is "at rest" (futex_wait).
It's impossible to end the process by CTRL+C or "System Monitor / end the process"
I have to kill the process.

The log is the following :
libjack.so.0: cannot open shared object file: No such file or directory
get fences failed: -1
param: 6, val: 0
>>> Playing with alsa
-!- alsa::hw_config::set: snd_pcm_hw_params_set_access failed: Invalid argument
>>> Playing with pa19
>>> Not scanning: /home/vivien/.ultrastar/songs/ (no such directory)
>>> Not scanning: /usr/local/share/games/ultrastar/songs/ (no such directory)
>>> Not scanning: /usr/local/share/ultrastar/songs/ (no such directory)
>>> Scanning /usr/share/games/ultrastar/songs/
  /usr/share/games/ultrastar/songs/Tryo - Toi et moi/ >>> Recording from alsa
1 songs loaded
>>> Not scanning: /usr/share/ultrastar/songs/ (no such directory)
-!- alsa::hw_config::set: snd_pcm_hw_params_set_access failed: Invalid argument
>>> Recording from gst
Input #0, ogg, from '/usr/share/games/performous/themes/lima/menu.ogg':
  Duration: 00:02:06.04, start: 0.000000, bitrate: 112 kb/s
    Stream #0.0: Audio: vorbis, 44100 Hz, stereo, s16, 112 kb/s
Resampling audio from 2 channel(s) at 44100Hz to 2 channels at 48000Hz
Empty audio frame
Exception from playback callback: accessing 'front()' on empty container
Exception from playback callback: accessing 'front()' on empty container
Exception from playback callback: accessing 'front()' on empty container
Exception from playback callback: accessing 'front()' on empty container
Exception from playback callback: accessing 'front()' on empty container
Exception from playback callback: accessing 'front()' on empty container
Exception from playback callback: accessing 'front()' on empty container
...

and so on...

Thanks for your reply to my problem.

Best Regards.