I did everything you said save for one slight difference, you have to open Thunderbird first before you paste the old files into the ~/.thunderbird folder, cause until you open Thunderbird that file does not exist. I tried to paste the old files and couldn't find the file, I then opened Thunderbird set up both of my e-mail accounts, closed Thunderbird, searched for the ~/.thunderbird folder, found it this time, copied the saved files into it, restarted Thunderbird, and wallah, all of my e-mails and settings were there.