Made sure secure transactions (anything requiring user credentials) are sent over SSL (https).
Thanks to Rick van der Zwet for pointing out the problem!
DORKYPANTS When I click the Done button after typing in my Twitter username and password, nothing happens; i.e., the widget doesn't flip back to its front side. Not good. Reverting to 2.0.3 (Version 2.0.4)
ANDREW SCOTT This is my favourite Twitter widget and I've tried quite a few. It's responsive and easy to use. My one complaint is that I can't resize the window to see a lot more tweets at once but apart from that it's pretty good. (Version 2.0.2)