Also faced the problem login to twitter after flashing.
1) Flash my device firmware by product code
2) When you first turn set up a Nokia account
3) N9 has detected a standard upgrade, including twitter, version - 1.3.95+0m8
4) Install all the updates.

When you try to set up an account twitter get the following:
1) Enter the name for twitter
2) turn on the login page, and I enter the password
3) click on the "authorize" application
4) After that, I have to go back to the native twitter, but this does not happen .. I remained on the login page application and available only buttons - "Cancel"