Can't complete Twitter authorization process

1. Connect to Twitter account for first time. => "Give permission to use your Twitter account" window appears.
2. Enter password. Press "Authorize app".
3. A new page loads, "Log in to Twitter", with another login form. (Trying to log in again just repeats this step.)

Maybe this problem is outside the scope of TorBirdy. I confirmed I can log in to Twitter using Tor Browser with the same username and password.

I've been using TorBirdy with this same account on another machine for over a year without issue.

TorBirdy 0.1.4, Icedove 31.8.0

Trac:
Username: bernie.allen