update manager crashes when clearing old version

[apa]

Binary package hint: update-manager

Kubuntu 6.10 Edgy
I follow instructions for update to new version Feisty. Update Manager download all package and it was clearing old version then crashes and leave the system unbootable.
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Traceback (most recent call last):
  File "/tmp/kde-root/adept_managerA2JdQa.tmp-extract/dist-upgrade.py", line 56, in ?
    app.run()
  File "/tmp/kde-root/adept_managerA2JdQa.tmp-extract/DistUpgradeControler.py", line 977, in run
    self.fullUpgrade()
  File "/tmp/kde-root/adept_managerA2JdQa.tmp-extract/DistUpgradeControler.py", line 966, in fullUpgrade
    self.doPostUpgrade()
  File "/tmp/kde-root/adept_managerA2JdQa.tmp-extract/DistUpgradeControler.py", line 709, in doPostUpgrade
    self._view.getTerminal().call([script], hidden=True)
  File "/tmp/kde-root/adept_managerA2JdQa.tmp-extract/DistUpgradeView.py", line 72, in call
    subprocess.call(cmd)
  File "subprocess.py", line 413, in call
    return Popen(*args, **kwargs).wait()
  File "subprocess.py", line 543, in __init__
    errread, errwrite)
  File "subprocess.py", line 975, in _execute_child
    raise child_exception
OSError: [Errno 13] Permission denied