It seems as if you haven't read the thread at all... well, to remove the authentication error, you will hafta either 1) download Firewall iP from Cydia (requires a jailbroken iPhone) or 2) edit the hosts file to block Garmin's servers (again, requires a jailbroken iPhone). To load your maps, download the maps from torrent / any other site, and place them in your garmin-app/storage-usa/.System folder.
Now a question from me: has anyone gotten the Route Simulator plist working in Garmin 2.2? I have been unable to get the route simulator to work. The maps choice works though.
Garmin 2.2 with no maps is available for download (70-some MB) available via Apptrackr.cd