diff --git a/IPython/core/display.py b/IPython/core/display.py
index 82a9187..5cd6482 100644
--- a/IPython/core/display.py
+++ b/IPython/core/display.py
@@ -117,7 +117,7 @@ def display(*objs, **kwargs):
 
         # If _ipython_display_ is defined, use that to display this object.  If
         # it returns NotImplemented, use the _repr_ logic (default).
-        if not hasattr(obj, '_ipython_display_') or isinstance(obj._ipython_display_(**kwargs), NotImplemented):
+        if not hasattr(obj, '_ipython_display_') or obj._ipython_display_(**kwargs) == NotImplemented:
             if raw:
                 publish_display_data('display', obj, metadata)
             else:            
diff --git a/IPython/html/static/notebook/js/widgets/widget_bool.js b/IPython/html/static/notebook/js/widgets/widget_bool.js
index b3c032f..bb78b96 100644
--- a/IPython/html/static/notebook/js/widgets/widget_bool.js
+++ b/IPython/html/static/notebook/js/widgets/widget_bool.js
@@ -15,7 +15,7 @@
  **/
 
 define(["notebook/js/widgets/widget"], function(widget_manager){
-    var CheckboxView = IPython.DOMWidgetView.extend({
+    var CheckBoxView = IPython.DOMWidgetView.extend({
       
         // Called when view is rendered.
         render : function(){
@@ -60,12 +60,12 @@ define(["notebook/js/widgets/widget"], function(widget_manager){
                     this.$label.show();
                 }
             }
-            return CheckboxView.__super__.update.apply(this);
+            return CheckBoxView.__super__.update.apply(this);
         },
         
     });
 
-    widget_manager.register_widget_view('CheckboxView', CheckboxView);
+    widget_manager.register_widget_view('CheckBoxView', CheckBoxView);
 
     var ToggleButtonView = IPython.DOMWidgetView.extend({
       
diff --git a/IPython/html/widgets/widget.py b/IPython/html/widgets/widget.py
index d6b64a9..25bbc9c 100644
--- a/IPython/html/widgets/widget.py
+++ b/IPython/html/widgets/widget.py
@@ -166,7 +166,7 @@ class Widget(LoggingConfigurable):
     def _handle_property_changed(self, name, old, new):
         """Called when a property has been changed."""
         # Make sure this isn't information that the front-end just sent us.
-        if should_send_property(self, name, new):
+        if self.should_send_property(name, new):
             # Send new state to front-end
             self.send_state(key=name)
 
diff --git a/IPython/html/widgets/widget_bool.py b/IPython/html/widgets/widget_bool.py
index 830f55a..0ad088a 100644
--- a/IPython/html/widgets/widget_bool.py
+++ b/IPython/html/widgets/widget_bool.py
@@ -27,6 +27,6 @@ class CheckBoxWidget(DOMWidget):
     description = Unicode('', help="Description of the boolean (label).", sync=True) 
     disabled = Bool(False, help="Enable or disable user changes.", sync=True)
 
-class ToggleButtonWidget(CheckboxWidget):
+class ToggleButtonWidget(CheckBoxWidget):
     view_name = Unicode('ToggleButtonView', sync=True)
     
\ No newline at end of file
diff --git a/IPython/html/widgets/widget_selection.py b/IPython/html/widgets/widget_selection.py
index f818963..4605e5a 100644
--- a/IPython/html/widgets/widget_selection.py
+++ b/IPython/html/widgets/widget_selection.py
@@ -29,13 +29,13 @@ class ToggleButtonsWidget(DOMWidget):
     description = Unicode(help="Description of the value this widget represents", sync=True)
 
 
-class DropdownWidget(SelectionWidget):
+class DropdownWidget(ToggleButtonsWidget):
     view_name = Unicode('DropdownView', sync=True)
 
 
-class RadioButtonsWidget(SelectionWidget):
+class RadioButtonsWidget(ToggleButtonsWidget):
     view_name = Unicode('RadioButtonsView', sync=True)
     
 
-class ListBoxWidget(SelectionWidget):
+class ListBoxWidget(ToggleButtonsWidget):
     view_name = Unicode('ListBoxView', sync=True)