'ascii' codec can't decode byte 0xc3 in position 0: ordinal not in range(128)

[lipstick]

I get this error while trying to change Ubuntu reposities on Ubuntu 11.04

Traceback (most recent call last):
  File "/usr/lib/python2.7/dist-packages/aptdaemon/worker.py", line 144, in _process_transaction
    self._lock_cache()
  File "/usr/lib/python2.7/dist-packages/aptdaemon/worker.py", line 794, in _lock_cache
    self.trans.status_details = msg % error.process
  File "/usr/lib/python2.7/dist-packages/aptdaemon/core.py", line 537, in _set_status_details
    self._status_details = dbus.String(text)
UnicodeDecodeError: 'ascii' codec can't decode byte 0xc3 in position 0: ordinal not in range(128)

Thanks