Rails - Devise - Warden and InvalidAuthenticityToken

Hi

I've just uploaded my new website to my server and, after a couple of teething problems, seem to be hitting problems when I am using devise and warden to authenticate users etc.

The following is the error message with sensitive information removed:

Processing RegistrationsController#create (for 81.111.90.194 at 2010-08-19 21:35:43) [POST]   Parameters: {"commit"=>"Sign up", "action"=>"create", "authenticity_token"=>"XXXXXXXREMOVEDXXXXXXX", "controller"=>"registrations", "user"=>{"dob"=>"XXXXXXX", "password_confirmation"=>"[FILTERED]", "firstname"=>"XXX", "password"=>"[FILTERED]", "surname"=>"XXX", "email"=>"XXXXXX"}}

ActionController::InvalidAuthenticityToken (ActionController::InvalidAuthenticityToken):   warden (0.10.7) [v] lib/warden/manager.rb:35:in `call'   warden (0.10.7) [v] lib/warden/manager.rb:34:in `catch'   warden (0.10.7) [v] lib/warden/manager.rb:34:in `call'

Rendering /home/enigmaho/rails_apps/newwt/public/422.html (422 Unprocessable Entity)

I have no real idea what is going wrong. It works OK on my development server at home, and everything else seems to work barring this.

My environment.rb file has the following lines:

  config.gem 'warden'   config.gem 'devise'

And they have been installed in my plugins/gems directory using "rake gems:unpack"

I'm using Rails 2.3.8 if that's any help.

Any help would be excellent!

Darren