Okay, this definitely looks like a bug in the restful_authentication plugin.
Look at the first comment here:
This seems to have been introduced lately, the last time I used
restful_authentication it generated
redirect_to :controller => '/session', :action => 'new'
I don't know if Rick has an official bug tracking site for his plugins
(you'd think he'd be using Lighthouse <G>) so I've changed the subject
in hopes he might be more likely to read this.