[orca-list] trace back message

[jose vilmar estacio de souza <vilmar informal com br>]

Hi all.
I don't no how, I don't why but I found the following messages in debug 
output from orca.

vvvvv PROCESS OBJECT EVENT object:state-changed:focused vvvvv
OBJECT EVENT: object:state-changed:focused             detail=(1,0,None)
    app.name='Thunderbird' name='None' role='table cell' state='enabled 
focusable focused opaque selectable selected sensitive showing vertical 
visible' relations='node child of'
Finding top-level object for source.name=
--> obj.name=
--> obj.name=
--> obj.name=
--> obj.name=Inbox - informal - Mozilla Thunderbird
Finding top-level object for source.name=
--> obj.name=
--> obj.name=
--> obj.name=
--> obj.name=Inbox - informal - Mozilla Thunderbird
LOCUS OF FOCUS: app='Thunderbird' name='[Bug 618589] when debugging in 
eclipse, sometimes orca reads the same line twice' role='table cell'
                event='object:state-changed:focused'

Traceback (most recent call last):
  File 
"/data/software/orca/dev/lib/python2.6/site-packages/orca/focus_tracking_presenter.py", 
line 709, in _processObjectEvent
    s.processObjectEvent(event)
  File 
"/data/software/orca/dev/lib/python2.6/site-packages/orca/script.py", 
line 383, in processObjectEvent
    self.listeners[key](event)
  File 
"/data/software/orca/dev/lib/python2.6/site-packages/orca/scripts/apps/Thunderbird/script.py", 
line 456, in onStateFocused
    Gecko.Script.onStateChanged(self, event)
  File 
"/data/software/orca/dev/lib/python2.6/site-packages/orca/scripts/toolkits/Gecko/script.py", 
line 1824, in onStateChanged
    default.Script.onStateChanged(self, event)
  File 
"/data/software/orca/dev/lib/python2.6/site-packages/orca/default.py", 
line 2982, in onStateChanged
    self.onFocus(event)
  File 
"/data/software/orca/dev/lib/python2.6/site-packages/orca/scripts/apps/Thunderbird/script.py", 
line 277, in onFocus
    orca.setLocusOfFocus(event, acc, force=force)
  File 
"/data/software/orca/dev/lib/python2.6/site-packages/orca/orca.py", line 
263, in setLocusOfFocus
    orca_state.locusOfFocus)
  File 
"/data/software/orca/dev/lib/python2.6/site-packages/orca/focus_tracking_presenter.py", 
line 1035, in locusOfFocusChanged
    newLocusOfFocus)
  File 
"/data/software/orca/dev/lib/python2.6/site-packages/orca/scripts/apps/Thunderbird/script.py", 
line 398, in locusOfFocusChanged
    string = orca_state.lastNonModifierKeyEvent.event_string
AttributeError: 'NoneType' object has no attribute 'event_string'

^^^^^ PROCESS OBJECT EVENT object:state-changed:focused ^^^^^