I used to have Simple Captcha installed, but since I removed it I got all kinds of problems with login.
Processing UsersController#login (for 188.177.122.179 at 2010-09-19 12:21:09) [POST] Parameters: {"commit"=>"OK", "authenticity_token"=>"/ Y0aZETCsMhyI3CkrZJK6O2NaLEoi+LRe8ZuDPWU9kc=", "user"=>{"remember_me"=>"0", "password"=>"xxxxx", "screen_name"=>"rune"}}
ActionController::InvalidAuthenticityToken (ActionController::InvalidAuthenticityToken): /home/heroku_rack/lib/static_assets.rb:9:in `call' /home/heroku_rack/lib/last_access.rb:15:in `call' /home/heroku_rack/lib/date_header.rb:14:in `call' thin (1.2.6) lib/thin/connection.rb:76:in `pre_process' thin (1.2.6) lib/thin/connection.rb:74:in `catch' thin (1.2.6) lib/thin/connection.rb:74:in `pre_process' thin (1.2.6) lib/thin/connection.rb:57:in `process' thin (1.2.6) lib/thin/connection.rb:42:in `receive_data' eventmachine (0.12.10) lib/eventmachine.rb:256:in `run_machine' eventmachine (0.12.10) lib/eventmachine.rb:256:in `run' thin (1.2.6) lib/thin/backends/base.rb:57:in `start' thin (1.2.6) lib/thin/server.rb:156:in `start' thin (1.2.6) lib/thin/controllers/controller.rb:80:in `start' thin (1.2.6) lib/thin/runner.rb:177:in `send' thin (1.2.6) lib/thin/runner.rb:177:in `run_command' thin (1.2.6) lib/thin/runner.rb:143:in `run!' thin (1.2.6) bin/thin:6 /usr/ruby1.8.7/bin/thin:19:in `load' /usr/ruby1.8.7/bin/thin:19