Indicator crashes when start in Terminal

[Dooitze de Jong]

I typed the following command: indicator-applet

I got the error here below:

Traceback (most recent call last):
  File "/usr/bin/indicator-cpufreq", line 79, in <module>
    from indicator_cpufreq.indicator import MyIndicator
  File "/usr/lib/pymodules/python2.7/indicator_cpufreq/indicator.py", line 26, in <module>
    import appindicator
  File "/usr/lib/python2.7/dist-packages/appindicator/__init__.py", line 27, in <module>
    from _appindicator import *
ImportError: /usr/lib/python2.7/dist-packages/appindicator/_appindicator.so: undefined symbol: app_indicator_get_accessible_desc

My hardware details:
http://pastebin.ubuntu.com/573102/

My software details:
Ubuntu 11.04 Updated 27 February 2011
Kernel: 2.6.38-1