I have been attempting to set up Thunderbird from a default install of Ubuntu 12.04LTS Desktop. Attempting to click on the inbox gives:
The current operation on Inbox did not succeed. The mail server for account firstname.lastname@example.org responded: System error(Failure)
I've also changed the servers to imap.gmail.com from imap.googlemail.com, but to no avail. I see my folders, but I can't see inside them. I've also enabled smtp, pop, and imap from the google account settings side from within the web client.