title: RoR: ActiveRecord, NoMethodError in models that are extended from AR
body: <p>I have the following models set up:
  <code><pre>
  class Qa::Base &lt; ActiveRecord::Base
    self.abstract_class = true
    Qa::Base.establish_connection("qa_audit_#{RAILS_ENV}")
  end</p>
  
  <p>class Qa::ErrorType &lt; Qa::Base
    set_table_name "error_types"<br>
    # Associations
    has_many :errors, :class_name => 'Qa::Error'
    has_many :evaluations, :class_name => 'Qa::Evaluation', :through => :errors<br>
    # Validations
    validates_presence_of :content
    validates_uniqueness_of :content
  end
  </pre></code></p>
  
  <p>But when saving/validating a model I keep hitting the following NoMethodErrors:</p>
  
  <p><code><pre>NoMethodError (undefined method `add_on_blank' for #Class:0x23a3020):</pre></code></p>
  
  <p>Eg:
  <code><pre>
  e = Qa::ErrorType.first<br>
  e.valid?
  </pre></code></p>
  
  <p>produces</p>
  
  <p><code><pre>
  NoMethodError: undefined method <code>add_on_blank' for #&lt;Class:0x223eeb4&gt;
      from /opt/local/lib/ruby/gems/1.8/gems/activerecord-2.3.8/lib/active_record/base.rb:1994:in</code>method_missing_without_paginate'
      from /opt/local/lib/ruby/gems/1.8/gems/will_paginate-2.3.14/lib/will_paginate/finder.rb:170:in <code>method_missing'
      from /opt/local/lib/ruby/gems/1.8/gems/activerecord-2.3.8/lib/active_record/associations/association_collection.rb:380:in</code>send'
      from /opt/local/lib/ruby/gems/1.8/gems/activerecord-2.3.8/lib/active_record/associations/association_collection.rb:380:in <code>method_missing_without_paginate'
      from /opt/local/lib/ruby/gems/1.8/gems/activerecord-2.3.8/lib/active_record/base.rb:2178:in</code>with_scope'
      from /opt/local/lib/ruby/gems/1.8/gems/activerecord-2.3.8/lib/active_record/associations/association_proxy.rb:207:in <code>send'
      from /opt/local/lib/ruby/gems/1.8/gems/activerecord-2.3.8/lib/active_record/associations/association_proxy.rb:207:in</code>with_scope'
      from /opt/local/lib/ruby/gems/1.8/gems/activerecord-2.3.8/lib/active_record/associations/association_collection.rb:376:in <code>method_missing_without_paginate'
      from /opt/local/lib/ruby/gems/1.8/gems/will_paginate-2.3.14/lib/will_paginate/finder.rb:170:in</code>method_missing'
      from /opt/local/lib/ruby/gems/1.8/gems/activerecord-2.3.8/lib/active_record/validations.rb:599:in <code>validates_presence_of'
      from /opt/local/lib/ruby/gems/1.8/gems/activesupport-2.3.8/lib/active_support/callbacks.rb:182:in</code>call'
      from /opt/local/lib/ruby/gems/1.8/gems/activesupport-2.3.8/lib/active_support/callbacks.rb:182:in <code>evaluate_method'
      from /opt/local/lib/ruby/gems/1.8/gems/activesupport-2.3.8/lib/active_support/callbacks.rb:166:in</code>call'
      from /opt/local/lib/ruby/gems/1.8/gems/activesupport-2.3.8/lib/active_support/callbacks.rb:90:in <code>run'
      from /opt/local/lib/ruby/gems/1.8/gems/activesupport-2.3.8/lib/active_support/callbacks.rb:90:in</code>each'
      from /opt/local/lib/ruby/gems/1.8/gems/activesupport-2.3.8/lib/active_support/callbacks.rb:90:in <code>send'
      from /opt/local/lib/ruby/gems/1.8/gems/activesupport-2.3.8/lib/active_support/callbacks.rb:90:in</code>run'
      from /opt/local/lib/ruby/gems/1.8/gems/activesupport-2.3.8/lib/active_support/callbacks.rb:276:in <code>run_callbacks'
      from /opt/local/lib/ruby/gems/1.8/gems/activerecord-2.3.8/lib/active_record/validations.rb:1110:in</code>valid_without_callbacks?'
      from /opt/local/lib/ruby/gems/1.8/gems/activerecord-2.3.8/lib/active_record/callbacks.rb:315:in `valid?'
  </pre></code></p>
  
  <p>I have used the same code pattern elsewhere in the same application before and that portion still works fine (all the validations work as they are supposed to). </p>
  
  <p>Can someone shed some light on what I am doing wrong.</p>