SystemStackError in WelcomeController#complete

stack level too deep

RAILS_ROOT: /home/donp/src/ruby/rails/catmystuff
Application Trace | Framework Trace | Full Trace

vendor/rails/activerecord/lib/active_record/attribute_methods.rb:186:in `method_missing'
vendor/rails/activerecord/lib/active_record/attribute_methods.rb:194:in `method_missing'
vendor/rails/activerecord/lib/active_record/associations/association_proxy.rb:124:in `send'
vendor/rails/activerecord/lib/active_record/associations/association_proxy.rb:124:in `method_missing'
lib/login.rb:7:in `current_user='
app/controllers/welcome_controller.rb:60:in `complete'
/usr/bin/mongrel_rails:16:in `load'
/usr/bin/mongrel_rails:16