Comment 11 for bug 1043752

I can reproduce this with:
$ mkdir /tmp/äää
$ (cd /tmp/äää ; apt-get download 2vcard)
$ software-center /tmp/äää/2vcard*.deb

click on "install" and authenticate:

2012-10-08 10:21:14,318 - softwarecenter.backend - ERROR - error in _on_trans_finished 'Error: An unhandled error occured
There seems to be a programming error in aptdaemon. This is the software that allows you to install/remove software and to perform other package management related tasks.

Traceback (most recent call last):
  File "/usr/lib/python3/dist-packages/aptdaemon/worker.py", line 1181, in _simulate
    trans.unauthenticated, trans.high_trust_packages = self.__simulate(trans)
  File "/usr/lib/python3/dist-packages/aptdaemon/worker.py", line 1239, in __simulate
    deb = self.install_file(trans, simulate=True, **trans.kwargs)
  File "/usr/lib/python3/dist-packages/aptdaemon/worker.py", line 740, in install_file
    deb = self._check_deb_file(trans, path, force)
  File "/usr/lib/python3/dist-packages/aptdaemon/worker.py", line 1326, in _check_deb_file
    if not os.path.isfile(path):
  File "/usr/lib/python3.2/genericpath.py", line 29, in isfile
    st = os.stat(path)
UnicodeEncodeError: 'ascii' codec can't encode characters in position 5-7: ordinal not in range(128)
'