Listen does not open .mp3 files from the command line or by double-clicking on them

Binary package hint: listen

Ok, this is my first post. I hope i'm not making any error:
I'm using Xubuntu 8.10 and Listen 0.5
If i launch listen i can listen my mp3 files selecting them from the library, but if i just double-click on them while listen is not launched, nothing happens.

Moreover if i use the terminal:

$ listen /home/rent0n/Music/Song.mp3

I get this error:

Error grabbing key 174, 0x909e400
No iPod support
location: /usr/lib/xulrunner-1.9.0.5/libxpcom.so
before 3
Traceback (most recent call last):
  File "/usr/lib/listen/listen.py", line 218, in <module>
    ListenApp()
  File "/usr/lib/listen/listen.py", line 150, in __init__
    option.run_load(bonobo_client)
  File "/usr/lib/listen/option_parser.py", line 105, in run_load
    ret = client.msg_send("add",("play",self.convert_args_to_uris_string(self.args)))
AttributeError: 'NoneType' object has no attribute 'msg_send'

Thank you.