Restful_plugin with --stateful

Hi everyone,
I am trying to implement the restful_authentication plug in with
–include-activation and --stateful options. Installed the plug in
acts_as_sate_machine also. But when I am trying to save the user model I
get an error
NoMethodError in UsersController#create

undefined method `to_sym’ for #State:0x668b52c

RAILS_ROOT: E:/INSTAN~1/rails_apps/nanny_project
Application Trace | Framework Trace | Full Trace

E:/INSTAN~1/ruby/lib/ruby/gems/1.8/gems/activerecord-2.0.2/lib/active_record/attribute_methods.rb:205:in
method_missing' E:/INSTAN~1/ruby/lib/ruby/gems/1.8/gems/activerecord-2.0.2/lib/active_record/associations/association_proxy.rb:125:insend’
E:/INSTAN~1/ruby/lib/ruby/gems/1.8/gems/activerecord-2.0.2/lib/active_record/associations/association_proxy.rb:125:in
method_missing' vendor/plugins/acts_as_state_machine/lib/acts_as_state_machine.rb:146:incurrent_state’
vendor/plugins/acts_as_state_machine/lib/acts_as_state_machine.rb:89:in
next_states' vendor/plugins/acts_as_state_machine/lib/acts_as_state_machine.rb:89:inselect’
vendor/plugins/acts_as_state_machine/lib/acts_as_state_machine.rb:89:in
next_states' vendor/plugins/acts_as_state_machine/lib/acts_as_state_machine.rb:93:infire’
vendor/plugins/acts_as_state_machine/lib/acts_as_state_machine.rb:201:in
register!' app/controllers/users_controller.rb:21:increate’
What may be reason? do we need to write some thing extra for including
–stateful option with restful_authentication plugin. I am newbie in ROR
and using these for the first time. Please help.