Orca hangs on startup

[Abdelaziz Yakout]

when I start orca manually , it hangs on start screen as shown in the attached file
when I run it from terminal it gives the following:
"lyooozy@uzi-pc:~$ lsb_release -rd
Description: Ubuntu 11.04
Release: 11.04
yooozy@uzi-pc:~$ orca --replace
process 3988: arguments to dbus_connection_send_with_reply_and_block() were incorrect, assertion "connection != NULL" failed in file dbus-connection.c line 3524.
This is normally a bug in some application using the D-Bus library.
process 3988: arguments to dbus_connection_ref() were incorrect, assertion "connection != NULL" failed in file dbus-connection.c line 2633.
This is normally a bug in some application using the D-Bus library.
process 3988: arguments to dbus_connection_send_with_reply() were incorrect, assertion "connection != NULL" failed in file dbus-connection.c line 3391.
This is normally a bug in some application using the D-Bus library.
process 3988: arguments to dbus_pending_call_set_notify() were incorrect, assertion "pending != NULL" failed in file dbus-pending-call.c line 597.
This is normally a bug in some application using the D-Bus library.
process 3988: arguments to dbus_connection_send_with_reply_and_block() were incorrect, assertion "connection != NULL" failed in file dbus-connection.c line 3524.
This is normally a bug in some application using the D-Bus library.
process 3988: arguments to dbus_connection_send_with_reply_and_block() were incorrect, assertion "connection != NULL" failed in file dbus-connection.c line 3524.
This is normally a bug in some application using the D-Bus library.
process 3988: arguments to dbus_connection_send_with_reply_and_block() were incorrect, assertion "connection != NULL" failed in file dbus-connection.c line 3524.
This is normally a bug in some application using the D-Bus library.
process 3988: arguments to dbus_connection_send_with_reply_and_block() were incorrect, assertion "connection != NULL" failed in file dbus-connection.c line 3524.
This is normally a bug in some application using the D-Bus library.
process 3988: arguments to dbus_connection_send_with_reply_and_block() were incorrect, assertion "connection != NULL" failed in file dbus-connection.c line 3524.
This is normally a bug in some application using the D-Bus library.
process 3988: arguments to dbus_connection_send_with_reply_and_block() were incorrect, assertion "connection != NULL" failed in file dbus-connection.c line 3524.
This is normally a bug in some application using the D-Bus library.
process 3988: arguments to dbus_connection_send_with_reply_and_block() were incorrect, assertion "connection != NULL" failed in file dbus-connection.c line 3524.
This is normally a bug in some application using the D-Bus library.
process 3988: arguments to dbus_connection_send_with_reply_and_block() were incorrect, assertion "connection != NULL" failed in file dbus-connection.c line 3524.
This is normally a bug in some application using the D-Bus library.
process 3988: arguments to dbus_connection_send_with_reply_and_block() were incorrect, assertion "connection != NULL" failed in file dbus-connection.c line 3524.
This is normally a bug in some application using the D-Bus library.
process 3988: arguments to dbus_connection_send_with_reply_and_block() were incorrect, assertion "connection != NULL" failed in file dbus-connection.c line 3524.
This is normally a bug in some application using the D-Bus library.
process 3988: arguments to dbus_connection_send_with_reply_and_block() were incorrect, assertion "connection != NULL" failed in file dbus-connection.c line 3524.
This is normally a bug in some application using the D-Bus library.
process 3988: arguments to dbus_connection_send_with_reply_and_block() were incorrect, assertion "connection != NULL" failed in file dbus-connection.c line 3524.
This is normally a bug in some application using the D-Bus library.
process 3988: arguments to dbus_connection_send_with_reply_and_block() were incorrect, assertion "connection != NULL" failed in file dbus-connection.c line 3524.
This is normally a bug in some application using the D-Bus library.
process 3988: arguments to dbus_connection_send_with_reply_and_block() were incorrect, assertion "connection != NULL" failed in file dbus-connection.c line 3524.
This is normally a bug in some application using the D-Bus library.
process 3988: arguments to dbus_connection_send_with_reply_and_block() were incorrect, assertion "connection != NULL" failed in file dbus-connection.c line 3524.
This is normally a bug in some application using the D-Bus library.
process 3988: arguments to dbus_connection_send_with_reply_and_block() were incorrect, assertion "connection != NULL" failed in file dbus-connection.c line 3524.
This is normally a bug in some application using the D-Bus library.
process 3988: arguments to dbus_connection_send_with_reply_and_block() were incorrect, assertion "connection != NULL" failed in file dbus-connection.c line 3524.
This is normally a bug in some application using the D-Bus library.
process 3988: arguments to dbus_connection_send_with_reply_and_block() were incorrect, assertion "connection != NULL" failed in file dbus-connection.c line 3524.
This is normally a bug in some application using the D-Bus library.
process 3988: arguments to dbus_connection_send_with_reply_and_block() were incorrect, assertion "connection != NULL" failed in file dbus-connection.c line 3524.
This is normally a bug in some application using the D-Bus library.
process 3988: arguments to dbus_connection_send_with_reply_and_block() were incorrect, assertion "connection != NULL" failed in file dbus-connection.c line 3524.
This is normally a bug in some application using the D-Bus library.
process 3988: arguments to dbus_connection_send_with_reply_and_block() were incorrect, assertion "connection != NULL" failed in file dbus-connection.c line 3524.
This is normally a bug in some application using the D-Bus library.
process 3988: arguments to dbus_connection_send_with_reply_and_block() were incorrect, assertion "connection != NULL" failed in file dbus-connection.c line 3524.
This is normally a bug in some application using the D-Bus library.
process 3988: arguments to dbus_connection_send_with_reply_and_block() were incorrect, assertion "connection != NULL" failed in file dbus-connection.c line 3524.
This is normally a bug in some application using the D-Bus library.
process 3988: arguments to dbus_connection_send_with_reply_and_block() were incorrect, assertion "connection != NULL" failed in file dbus-connection.c line 3524.
This is normally a bug in some application using the D-Bus library.
process 3988: arguments to dbus_connection_send_with_reply_and_block() were incorrect, assertion "connection != NULL" failed in file dbus-connection.c line 3524.
This is normally a bug in some application using the D-Bus library.
process 3988: arguments to dbus_connection_send_with_reply_and_block() were incorrect, assertion "connection != NULL" failed in file dbus-connection.c line 3524.
This is normally a bug in some application using the D-Bus library.

** (orca:3988): WARNING **: Couldn't get application list: (null)
Traceback (most recent call last):
  File "<string>", line 1, in <module>
  File "/usr/lib/pymodules/python2.7/orca/orca.py", line 2283, in main
    init(pyatspi.Registry)
  File "/usr/lib/pymodules/python2.7/orca/orca.py", line 1993, in init
    loadUserSettings()
  File "/usr/lib/pymodules/python2.7/orca/orca.py", line 1579, in loadUserSettings
    _eventManager.activate()
  File "/usr/lib/pymodules/python2.7/orca/event_manager.py", line 72, in activate
    win = orca_state.activeScript.utilities.activeWindow()
  File "/usr/lib/pymodules/python2.7/orca/script_utilities.py", line 146, in activeWindow
    apps = Utilities.knownApplications()
  File "/usr/lib/pymodules/python2.7/orca/script_utilities.py", line 910, in knownApplications
    pyatspi.Registry.getDesktop(0))
TypeError: 'NoneType' object is not iterable"

PS: I'm new to Ubuntu, let me if further info is needed, thaks.

ProblemType: Bug
DistroRelease: Ubuntu 11.04
Package: gnome-orca 3.0.0-0ubuntu2
ProcVersionSignature: Ubuntu 2.6.38-10.46-generic 2.6.38.7
Uname: Linux 2.6.38-10-generic i686
Architecture: i386
Date: Sat Aug 13 05:15:20 2011
ExecutablePath: /usr/bin/orca
InstallationMedia: Ubuntu 11.04 "Natty Narwhal" - Release i386 (20110427.1)
InterpreterPath: /bin/dash
PackageArchitecture: all
ProcEnviron:
 SHELL=/bin/bash
 LANG=en_US.UTF-8
 LANGUAGE=en_US:en
SourcePackage: gnome-orca
UpgradeStatus: No upgrade log present (probably fresh install)