uninitialized constant Preferences::InstanceMethods::Preference

[jai-n]

trying to use in rails3.2.14

added gem ’preferences’ to gem file did bundle install seems to work
run the rails generate migration create_preferences,
edited to migration to create the table with timestamps
ran rake db:migrate
restarted rails server
added some prefs to user model
all working

tried to access a pref using @user.prefers_publish_profile
In user model i write like this
preference :publish_profile, :default => true

got uninitialized constant Preferences::InstanceMethods::Preference