upgrade tool crashed in "cleanup" stage

Binary package hint: update-manager

In upgrade form Kubuntu Edgy 6.10 to 7.04 beta using the suggested upgrade tool, update tool crashed in "cleaning up" stage as it was removing obsolete packages.
Output from the update too is:
Traceback (most recent call last):
  File "/tmp/kde-root/adept_manager5JdDHb.tmp-extract/dist-upgrade.py", line 56, in ?
    app.run()
  File "/tmp/kde-root/adept_manager5JdDHb.tmp-extract/DistUpgradeControler.py", line 977, in run
    self.fullUpgrade()
  File "/tmp/kde-root/adept_manager5JdDHb.tmp-extract/DistUpgradeControler.py", line 966, in fullUpgrade
    self.doPostUpgrade()
  File "/tmp/kde-root/adept_manager5JdDHb.tmp-extract/DistUpgradeControler.py", line 709, in doPostUpgrade
    self._view.getTerminal().call([script], hidden=True)
  File "/tmp/kde-root/adept_manager5JdDHb.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