Traceback (most recent call last):
  File "/usr/share/gtg/GTG/taskbrowser/browser.py", line 1495, in on_add_subtask
    self.open_task(task.get_id(),thisisnew=True)
  File "/usr/share/gtg/GTG/taskbrowser/browser.py", line 847, in open_task
    clipboard = self.clipboard)
  File "/usr/share/gtg/GTG/taskeditor/editor.py", line 199, in __init__
    self.pengine.onTaskLoad(self.te_plugin_api)
  File "/usr/share/gtg/GTG/core/plugins/engine.py", line 232, in onTaskLoad
    plugin.instance.onTaskOpened(plugin_api)
  File "/usr/share/gtg/GTG/plugins/tomboy/tomboy.py", line 169, in onTaskOpened
    self.addButtonToToolbar(plugin_api)
  File "/usr/share/gtg/GTG/plugins/tomboy/tomboy.py", line 122, in addButtonToToolbar
    pixbuf_new_from_file_at_size(tb_Taskbutton_image_path, 16, 16)
GError: Unrecognized image file format