I assume there's something obvious that I'm missing, but it's flying below my visual radar, because I've tried looking everywhere on the site.
I had exactly this problem last night. I googled "twisted password reset" and found this page
http://twistedmatrix.com/trac/reset_password
I got it to send me a reset password, but that password didn't work (as explained in my mailing list post I sent last night).
So, since I couldn't remember my username from before, I decided to just register for a new account. During registration, it informed me: "Warning: Another account or group already exists, who's name differs from <my name> only by case or is identical" So I was likely just trying to re-use the same username... It then took a few tries to guess at the right case for the previous username I had used. ...and so finally, I hit upon the right case, and it sent me an email with a new password *Which (as you've mentioned) doesn't work.* I've filed a website bug about the whole issue (should probably be 3 separate bugs, but I really don't have the patience): https://bugs.launchpad.net/twisted-website/+bug/1257934