GError in Battery Status : Unrecognized image format

[benjamin]

Traceback (most recent call last):
  File "/usr/lib/python2.7/dist-packages/awn/extras/awnlib.py", line 1580, in init_start
    applet_class(applet)
  File "/usr/share/avant-window-navigator/applets/battery/battery.py", line 85, in __init__
    self.check_status_cb()
  File "/usr/share/avant-window-navigator/applets/battery/battery.py", line 236, in check_status_cb
    self.draw_icon(icon)
  File "/usr/share/avant-window-navigator/applets/battery/battery.py", line 246, in draw_icon
    self.applet.icon.file(icon, size=awnlib.Icon.APPLET_SIZE)
  File "/usr/lib/python2.7/dist-packages/awn/extras/awnlib.py", line 476, in file
    icon = gtk.gdk.pixbuf_new_from_file_at_size(file, size, size)
GError: Format d'image non reconnu