diff --git a/test/list_test.rb b/test/list_test.rb
index ab27024..bef1c2d 100644
--- a/test/list_test.rb
+++ b/test/list_test.rb
@@ -9,6 +9,23 @@
 
 ActiveRecord::Base.establish_connection(:adapter => "sqlite3", :dbfile => ":memory:")
 
+def setup_db
+  ActiveRecord::Schema.define(:version => 1) do
+    create_table :mixins do |t|
+      t.column :pos, :integer
+      t.column :parent_id, :integer
+      t.column :created_at, :datetime      
+      t.column :updated_at, :datetime
+    end
+  end
+end
+
+def teardown_db
+  ActiveRecord::Base.connection.tables.each do |table|
+    ActiveRecord::Base.connection.drop_table(table)
+  end
+end
+
 class Mixin < ActiveRecord::Base
 end
 
@@ -18,6 +35,12 @@ class ListMixin < Mixin
   def self.table_name() "mixins" end
 end
 
+class ListMixinSub1 < ListMixin
+end
+
+class ListMixinSub2 < ListMixin
+end
+
 class ListWithStringScopeMixin < ActiveRecord::Base
   acts_as_list :column => "pos", :scope => 'parent_id = #{parent_id}'
 
@@ -28,20 +51,12 @@ def self.table_name() "mixins" end
 class ListTest < Test::Unit::TestCase
 
   def setup
-    ActiveRecord::Schema.define(:version => 1) do
-      create_table :mixins do |t|
-        t.integer :pos, :parent_id
-        t.timestamps
-      end
-    end
-
+    setup_db
     (1..4).each { |counter| ListMixin.create! :pos => counter, :parent_id => 5 }
   end
 
   def teardown
-    ActiveRecord::Base.connection.tables.each do |table|
-      ActiveRecord::Base.connection.drop_table(table)
-    end
+    teardown_db
   end
 
   def test_reordering
@@ -78,7 +93,7 @@ def test_next_prev
     assert_equal ListMixin.find(3), ListMixin.find(4).higher_item
     assert_nil ListMixin.find(4).lower_item
   end
-  
+
   def test_injection
     item = ListMixin.new(:parent_id => 1)
     assert_equal "parent_id = 1", item.scope_condition
@@ -175,3 +190,111 @@ def test_nil_scope
   end
 
 end
+
+class ListSubTest < Test::Unit::TestCase
+
+  def setup
+    setup_db
+    (1..4).each { |i| ((i % 2 == 1) ? ListMixinSub1 : ListMixinSub2).create! :pos => i, :parent_id => 5000 }
+  end
+
+  def teardown
+    teardown_db
+  end
+
+  def test_reordering
+    assert_equal [1, 2, 3, 4], ListMixin.find(:all, :conditions => 'parent_id = 5000', :order => 'pos').map(&:id)
+
+    ListMixin.find(2).move_lower
+    assert_equal [1, 3, 2, 4], ListMixin.find(:all, :conditions => 'parent_id = 5000', :order => 'pos').map(&:id)
+
+    ListMixin.find(2).move_higher
+    assert_equal [1, 2, 3, 4], ListMixin.find(:all, :conditions => 'parent_id = 5000', :order => 'pos').map(&:id)
+
+    ListMixin.find(1).move_to_bottom
+    assert_equal [2, 3, 4, 1], ListMixin.find(:all, :conditions => 'parent_id = 5000', :order => 'pos').map(&:id)
+
+    ListMixin.find(1).move_to_top
+    assert_equal [1, 2, 3, 4], ListMixin.find(:all, :conditions => 'parent_id = 5000', :order => 'pos').map(&:id)
+
+    ListMixin.find(2).move_to_bottom
+    assert_equal [1, 3, 4, 2], ListMixin.find(:all, :conditions => 'parent_id = 5000', :order => 'pos').map(&:id)
+
+    ListMixin.find(4).move_to_top
+    assert_equal [4, 1, 3, 2], ListMixin.find(:all, :conditions => 'parent_id = 5000', :order => 'pos').map(&:id)
+  end
+
+  def test_move_to_bottom_with_next_to_last_item
+    assert_equal [1, 2, 3, 4], ListMixin.find(:all, :conditions => 'parent_id = 5000', :order => 'pos').map(&:id)
+    ListMixin.find(3).move_to_bottom
+    assert_equal [1, 2, 4, 3], ListMixin.find(:all, :conditions => 'parent_id = 5000', :order => 'pos').map(&:id)
+  end
+
+  def test_next_prev
+    assert_equal ListMixin.find(2), ListMixin.find(1).lower_item
+    assert_nil ListMixin.find(1).higher_item
+    assert_equal ListMixin.find(3), ListMixin.find(4).higher_item
+    assert_nil ListMixin.find(4).lower_item
+  end
+
+  def test_injection
+    item = ListMixin.new("parent_id"=>1)
+    assert_equal "parent_id = 1", item.scope_condition
+    assert_equal "pos", item.position_column
+  end
+
+  def test_insert_at
+    new = ListMixin.create("parent_id" => 20)
+    assert_equal 1, new.pos
+
+    new = ListMixinSub1.create("parent_id" => 20)
+    assert_equal 2, new.pos
+
+    new = ListMixinSub2.create("parent_id" => 20)
+    assert_equal 3, new.pos
+
+    new4 = ListMixin.create("parent_id" => 20)
+    assert_equal 4, new4.pos
+
+    new4.insert_at(3)
+    assert_equal 3, new4.pos
+
+    new.reload
+    assert_equal 4, new.pos
+
+    new.insert_at(2)
+    assert_equal 2, new.pos
+
+    new4.reload
+    assert_equal 4, new4.pos
+
+    new5 = ListMixinSub1.create("parent_id" => 20)
+    assert_equal 5, new5.pos
+
+    new5.insert_at(1)
+    assert_equal 1, new5.pos
+
+    new4.reload
+    assert_equal 5, new4.pos
+  end
+
+  def test_delete_middle
+    assert_equal [1, 2, 3, 4], ListMixin.find(:all, :conditions => 'parent_id = 5000', :order => 'pos').map(&:id)
+
+    ListMixin.find(2).destroy
+
+    assert_equal [1, 3, 4], ListMixin.find(:all, :conditions => 'parent_id = 5000', :order => 'pos').map(&:id)
+
+    assert_equal 1, ListMixin.find(1).pos
+    assert_equal 2, ListMixin.find(3).pos
+    assert_equal 3, ListMixin.find(4).pos
+
+    ListMixin.find(1).destroy
+
+    assert_equal [3, 4], ListMixin.find(:all, :conditions => 'parent_id = 5000', :order => 'pos').map(&:id)
+
+    assert_equal 1, ListMixin.find(3).pos
+    assert_equal 2, ListMixin.find(4).pos
+  end
+
+end