RQT nodes not starting

edit

I have a clean ROS Indigo installation on an Ubuntu 64 14.04, but rqt nodes do not start. Here is the error message:

~/catkin_ws$ rosrun rqt_reconfigure rqt_reconfigure 
Traceback (most recent call last):
  File "/opt/ros/indigo/lib/rqt_reconfigure/rqt_reconfigure", line 6, in <module>
    from rqt_reconfigure.param_plugin import ParamPlugin
  File "/opt/ros/indigo/lib/python2.7/dist-packages/rqt_reconfigure/param_plugin.py", line 35, in <module>
    from rqt_gui_py.plugin import Plugin
  File "/opt/ros/indigo/lib/python2.7/dist-packages/rqt_gui_py/plugin.py", line 33, in <module>
    from qt_gui.plugin import Plugin as Base
  File "/opt/ros/indigo/lib/python2.7/dist-packages/qt_gui/plugin.py", line 31, in <module>
    from python_qt_binding.QtCore import QObject
  File "/opt/ros/indigo/lib/python2.7/dist-packages/python_qt_binding/__init__.py", line 55, in <module>
    from .binding_helper import loadUi, QT_BINDING, QT_BINDING_MODULES, QT_BINDING_VERSION  # @UnusedImport
  File "/opt/ros/indigo/lib/python2.7/dist-packages/python_qt_binding/binding_helper.py", line 262, in <module>
    getattr(sys, 'SELECT_QT_BINDING_ORDER', None),
  File "/opt/ros/indigo/lib/python2.7/dist-packages/python_qt_binding/binding_helper.py", line 90, in _select_qt_binding
    raise ImportError("Could not find Qt binding (looked for: %s):\n%s" % (', '.join(["'%s'" % b for b in binding_order]), '\n'.join(error_msgs)))
ImportError: Could not find Qt binding (looked for: 'pyqt', 'pyside'):
  ImportError for 'pyqt': /usr/lib/python2.7/dist-packages/PyQt4/QtCore.so: undefined symbol: _ZTI13QStateMachine
  ImportError for 'pyside': /usr/lib/x86_64-linux-gnu/libpyside-python2.7.so.1.2: undefined symbol: _Z9qBadAllocv

Thanks for your help!

Edit: Das Problem war, dass in LD_LIBRARY_PATH ein Pfad angegeben war, welcher wohl zu falschen Versionen geführt hat.