Comment 14 for bug 244453

Verified with the proposed package for natty.

Reproducing the problem (using a lucid test repository to trigger the 401, it doesn't matter that it's not natty):
root@li37-87:~# smart update aptsync-4256fab382bd1817c0c8c568a38ae5ea
Loading cache...
Updating cache... ########################################################################################## [100%]

Fetching information for 'lucid - main'...
-> https://ahasenack:*@private-ppa.launchpad.net/landscape/landscape-testing/ubuntu/dists/lucid/Release.gpg
Release.gpg ########################################################################################## [ 33%]
-> https://ahasenack:*@private-ppa.launchpad.net/landscape/landscape-testing/ubuntu/dists/lucid/Release
Release ########################################################################################## [ 66%]
error: Channel 'lucid - main' signed with unknown key

Updating the package:

root@li37-87:~# apt-get install smartpm-core python-smartpm
Reading package lists... Done
Building dependency tree
Reading state information... Done
smartpm-core is already the newest version.
The following packages were automatically installed and are no longer required:
  python-psycopg2 python-egenix-mxdatetime python-egenix-mxtools libpq5
Use 'apt-get autoremove' to remove them.
The following packages will be upgraded:
  python-smartpm
1 upgraded, 0 newly installed, 0 to remove and 4 not upgraded.
Need to get 285 kB of archives.
After this operation, 0 B of additional disk space will be used.
Do you want to continue [Y/n]?
Get:1 http://security.ubuntu.com/ubuntu/ natty-proposed/main python-smartpm i386 1.3-1.3ubuntu0.2 [285 kB]
Fetched 285 kB in 0s (384 kB/s)
(Reading database ... 28103 files and directories currently installed.)
Preparing to replace python-smartpm 1.3-1.3ubuntu0.1 (using .../python-smartpm_1.3-1.3ubuntu0.2_i386.deb) ...
Unpacking replacement python-smartpm ...
Processing triggers for python-support ...
Setting up python-smartpm (1.3-1.3ubuntu0.2) ...
Processing triggers for python-support ...

Trying smart again, now we get a nice 401 error:
root@li37-87:~# smart update aptsync-4256fab382bd1817c0c8c568a38ae5ea
Loading cache...
Updating cache... ########################################################################################## [100%]

Fetching information for 'lucid - main'...
-> https://ahasenack:*@private-ppa.launchpad.net/landscape/landscape-testing/ubuntu/dists/lucid/Release.gpg
Release.gpg [ 0%]
-> https://ahasenack:*@private-ppa.launchpad.net/landscape/landscape-testing/ubuntu/dists/lucid/Release
Release [ 0%]
error: Download of Release failed for channel 'lucid - main': The requested URL returned error: 401