What am I doing wrong here? I have been able to get the new row thing to work using a dataset, but this time I am using custom objects. I even changed my one class to inherit from BindingList<> instead of ObservableCollection<> and it still doesn't appear. Here is my code... 

<igDP:XamDataGrid Grid.Row="0"  Margin="10,5,10,5" Background="White" Theme="Aero" x:Name="MetrixRelationDefGrid">
        <igDP:XamDataGrid.FieldLayoutSettings>
          <igDP:FieldLayoutSettings MaxSelectedRecords="1" AddNewRecordLocation="OnTopFixed" AllowAddNew="True" AutoGenerateFields="False">
            <igDP:FieldLayoutSettings.DataRecordCellAreaGridTemplate>
              <ItemsPanelTemplate>
                <Grid>
                  <Grid.ColumnDefinitions>
                    <ColumnDefinition Width="75" />
                    <ColumnDefinition Width="150" />
                    <ColumnDefinition Width="150" />
                  </Grid.ColumnDefinitions>
                </Grid>
              </ItemsPanelTemplate>
            </igDP:FieldLayoutSettings.DataRecordCellAreaGridTemplate>
          </igDP:FieldLayoutSettings>
        </igDP:XamDataGrid.FieldLayoutSettings>
        <igDP:XamDataGrid.FieldLayouts>
          <igDP:FieldLayout Key="MetrixRelationDef">
            <igDP:FieldLayout.Fields>
              <igDP:Field Name="IsSelected" Label="Selected"/>
              <igDP:Field Name="ParentTableName" Label="Parent Table"/>
              <igDP:Field Name="RelatedTableName" Label="Related Table"/>
            </igDP:FieldLayout.Fields>
          </igDP:FieldLayout>
        </igDP:XamDataGrid.FieldLayouts>
      </igDP:XamDataGrid>

Binding bd = new Binding();
            bd.Source = metrixRelationDefs;
            MetrixRelationDefGrid.SetBinding(XamDataGrid.DataSourceProperty, bd);

using System;
using System.Collections.Generic;
using System.Text;
using System.Collections.ObjectModel;
using System.ComponentModel;

namespace MetrixStudio.CustomObjects
{
    public class MetrixRelationDefs : BindingList<MetrixRelationDef>
    {
    }

    public class MetrixRelationDef
    {
        private string _parentTableName;
        private string _relatedTableName;
        private bool _isSelected;
        private MetrixRelationMaps _relationMaps = new MetrixRelationMaps();
        private MetrixRelationConstraints _relationConstraints = new MetrixRelationConstraints();

        public MetrixRelationDef(string parentTableName, string relatedTableName)
        {
            this.ParentTableName = parentTableName;
            this.RelatedTableName = relatedTableName;
        }

        public MetrixRelationConstraints RelationConstraints
        {
            get { return _relationConstraints; }
            set { _relationConstraints = value; }
        }

        public MetrixRelationMaps RelationMaps
        {
            get { return _relationMaps; }
            set { _relationMaps = value; }
        }

        public bool IsSelected
        {
            get { return _isSelected; }
            set { _isSelected = value; }
        }

        public string ParentTableName
        {
            get { return _parentTableName; }
            set { _parentTableName = value; }
        }

        public string RelatedTableName
        {
            get { return _relatedTableName; }
            set { _relatedTableName = value; }
        }
    }

}