Fatal error upgrading Dapper to Edgy

Binary package hint: update-manager

Tried to upgrade from Ubuntu 6.06.1 to Edgy by running gksu "update-manager -c -d" on a terminal.

The update manager displays the option to upgrade, downloads some files, but then displays "A fatal error has occurred", with the following trace:

Traceback (most recent call last):

  File "/tmp/tmpMIb9Py/edgy", line 40, in ?
    app.run()

  File "/tmp/tmpMIb9Py/DistUpgradeControler.py", line 755, in run
    self.edgyUpgrade()

  File "/tmp/tmpMIb9Py/DistUpgradeControler.py", line 696, in edgyUpgrade
    if not self.updateSourcesList():

  File "/tmp/tmpMIb9Py/DistUpgradeControler.py", line 246, in updateSourcesList
    if not self.rewriteSourcesList(mirror_check=True):

  File "/tmp/tmpMIb9Py/DistUpgradeControler.py", line 173, in rewriteSourcesList
    distro.enable_component(self.sources, "main")

  File "/tmp/tmpMIb9Py/aptsources.py", line 634, in enable_component
    add_component_only_once(source, comps_per_dist)

  File "/tmp/tmpMIb9Py/aptsources.py", line 609, in add_component_only_once
    if comp in comps_per_dist[source.dist]:

KeyError: 'dapper-updates'

=== End of the trace ===

The Upgrade manager also suggests to include the following files:

* /var/log/dist-upgrade/main.log
* /var/log/dist-upgrade/apt.log

Also, i include the following info which i think can be useful:

denis@ubuntu-laptop:~$ uname -a
Linux ubuntu-laptop 2.6.15-27-686 #1 SMP PREEMPT Sat Sep 16 02:13:27 UTC 2006 i686 GNU/Linux

denis@ubuntu-laptop:~$ dpkg --version
Administrador de paquetes `dpkg' de Debian GNU/Linux, versión 1.13.11 (i386).

denis@ubuntu-laptop:~$ apt -version
apt 1.5.0_02