not logged in in subdomain?

For some reason my users get logged out when they switch to a
subdomain.
I have this in my environment:

    config.action_controller.session = {
      :session_key => '_app_session',
      :session_domain => 'mydomain.com',
      :secret => 'xxxx'
    }

Which I thought would cover that...

help!

You need to specify a wildcard domain for your auth cookie. The default is to use the entire domain.

Here's a blog post explaining how:

http://szeryf.wordpress.com/2008/01/21/cookie-handling-in-multi-domain-applications-in-ruby-on-rails/#

SH

thanks! I was missing the .
I'll give that a try

This is still not working for us.

we have:

  if RAILS_ENV == 'production'
    config.action_controller.session = {
      :session_key => '_site_session',
      :session_domain => '.site.com',
      :secret => 'xxxxx'
    }
  else
    config.action_controller.session = {
      :session_key => '_site_session',
      :session_domain => '.site.local',
      :secret => 'xxxxx'
    }
  end

and when users switch between sub domains or between no subdomain (we
don't use www... maybe that is the problem?) and a subdomain they need
to log in again.

Like I say, we are having no luck with this.
I am going to post a job on oDesk to hire someone to fix it... unless
anyone wants to apply directly to me.