problem when removing main package using tree

Funny enough, this is the stack trace I'm getting when interrupting the application:

2007-09-06 14:38:27,292 ERROR Error while undoing action <function _undo_create_
event at 0x018D0CB0>
Traceback (most recent call last):
  File ".\gaphor\services\undomanager.py", line 60, in execute
    action()
  File ".\gaphor\services\undomanager.py", line 323, in _undo_create_event
    component.handle(ElementDeleteEvent(factory, element))
  File "c:\documents and settings\arjan\home\py-site-packages\zope.component-3.4
dev_r72749-py2.4.egg\zope\component\_api.py", line 135, in handle
    for ignored in sitemanager.subscribers(objects, None):
  File "c:\documents and settings\arjan\home\py-site-packages\zope.component-3.4
dev_r72749-py2.4.egg\zope\component\registry.py", line 290, in subscribers
    return self.adapters.subscribers(objects, provided)
  File "c:\documents and settings\arjan\home\py-site-packages\zope.interface-3.4
.0-py2.4-win32.egg\zope\interface\adapter.py", line 535, in subscribers
    subscription(*objects)
  File ".\gaphor\services\undomanager.py", line 338, in undo_delete_event
    self.add_undo_action(_undo_delete_event)
  File ".\gaphor\services\undomanager.py", line 168, in add_undo_action
    component.handle(UndoManagerStateChanged(self))
  File "c:\documents and settings\arjan\home\py-site-packages\zope.component-3.4
dev_r72749-py2.4.egg\zope\component\_api.py", line 135, in handle
    for ignored in sitemanager.subscribers(objects, None):
  File "c:\documents and settings\arjan\home\py-site-packages\zope.component-3.4
dev_r72749-py2.4.egg\zope\component\registry.py", line 290, in subscribers
    return self.adapters.subscribers(objects, provided)
  File "c:\documents and settings\arjan\home\py-site-packages\zope.interface-3.4
.0-py2.4-win32.egg\zope\interface\adapter.py", line 531, in subscribers
    subscriptions = self.subscriptions(map(providedBy, objects), provided)
KeyboardInterrupt

Seems to work now.

deleting package works, now. but creating new one causes the same problem as described by me :) (no exception, though)

Confirmed.

Funny thing is the undomanager is displaye4d at the top of the stack trace.

Disabling the undo manager in setup.py and performing above mentioned steps result in a stack trace:

Traceback (most recent call last):
  File ".\gaphor\action.py", line 152, in _action_activate
    method()
  File ".\gaphor\transaction.py", line 13, in _transactional
    func(*args, **kwargs)
  File ".\gaphor\ui\mainwindow.py", line 533, in tree_view_create_package
    package.name = '%s package' % element.name
AttributeError: 'NoneType' object has no attribute 'name'

(In [2099]) Better handling when transactions are rolled back. Fix #68.