!! This is my User.rb model and I randomly I will get the error at the bottom... it will work sometimes and not some others for no apparent reason...


require 'digest/sha1'
class User < ActiveRecord::Base
  # Virtual attribute for the unencrypted password
  attr_accessor :password
  file_column :image
  validates_presence_of     :login, :email, :first_name, :last_name
  validates_presence_of     :password,                   :if => :password_required?
  validates_presence_of     :password_confirmation,      :if => :password_required?
  validates_length_of       :password, :within => 5..40, :if => :password_required?
  validates_confirmation_of :password,                   :if => :password_required?
  validates_length_of       :login,    :within => 3..40
  validates_length_of       :email,    :within => 3..100
  validates_uniqueness_of   :login, :email
  validates_format_of       :email, :with =>  %r{^[a-zA-Z0-9@\.]*}i
  before_save :encrypt_password
  searches_on :first_name, :last_name, :company_name, :email

  # Authenticates a user by their login name and unencrypted password.  Returns the user or nil.
  def self.authenticate(login, password)
    u = find_by_login(login) # need to get the salt
    u && u.authenticated?(password) ? u : nil
  end

  # Encrypts some data with the salt.
  def self.encrypt(password, salt)
    Digest::SHA1.hexdigest("--#{salt}--#{password}--")
  end

  # Encrypts the password with the user salt
  def encrypt(password)
    self.class.encrypt(password, salt)
  end

  def authenticated?(password)
    crypted_password == encrypt(password)
  end

  protected
  # before filter
  def encrypt_password
    return if password.blank?
    self.salt = Digest::SHA1.hexdigest("--#{Time.now.to_s}--#{login}--") if new_record?
    self.crypted_password = encrypt(password)
  end

  def password_required?
    crypted_password.blank? or not password.blank?
  end
end

NoMethodError (undefined method `authenticate' for User:Class):
    /usr/lib/ruby/gems/1.8/gems/activerecord-1.14.4/lib/active_record/base.rb:1129:in `method_missing'
    /app/controllers/account_controller.rb:14:in `login'
    /usr/lib/ruby/gems/1.8/gems/actionpack-1.12.5/lib/action_controller/base.rb:941:in `send'
    /usr/lib/ruby/gems/1.8/gems/actionpack-1.12.5/lib/action_controller/base.rb:941:in `perform_action_without_filters'...
...
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