I had, sort of, understood what you had said, in first place. Except that uninstalling the program does not remove, automatically, the profile. I have not uninstalled TB in years, so, it is possible that they have introduced a step to remove the profile. My profiles are, totally, independent of the program, and are located in a different folder, and issue not understood way back in the days of Netscape, and, still not fully understood.
Since the profiles remain intact, I, purposely, use new, yet untested versions of TB (the same applies to Firefox and Seamonkey) with an older profile. That's why I did not, fully, comprehend what you were doing.
And, I must say that it is important to say, at least, parts of the profile, i.e. the old folders. Although, at this time, I have no idea what is going on with your system.
I would create a new profile, which you can name, any way you wish. And, then make sure that you are, actually, using it. To give an example the folder in which TB is installed is: "C:\Program Files\Mozilla Thunderbird\.
And the shortcut is: "C:\Program Files\Mozilla Thunderbird\thunderbird.exe" . To bring up the profile manager you can modify the Target line, by adding -p, with a space before it, thus:"C:\Program Files\Mozilla Thu"C:\Program Files\Mozilla Thunderbird\thunderbird.exe" -p . If you called your new profile: TB 14, then to path to open your mail will be: "C:\Program Files\Mozilla Thunderbird\thunderbird.exe" -p TB14. If you did not do this, TB will open with your existing profile. I understand that you said :
Re-entered server information manually
, so from zero profiles, you had one, but, did you really remove the profile?
The profile folders are hidden, by default, and are in this location: C:\Documents and Settings\user_name\Application Data\Thunderbird.
UserAgent: Mozilla/5.0 (Windows NT 5.1) AppleWebKit/537.1 (KHTML, like Gecko) Chrome/21.0.1180.79 Safari/537.1