I am writing my first silverlight user control using the xamGrid and I am successfully displaying my data in the grid, but I cannot get sorting or filtering to work no matter what I try. The ItemsSource is set to KeyedCollection inheritor that implements INotifyCollectionChanged, but I could find no documentation on what is required of the data source to implement sorting and filtering.

The grid is setup as follows:

        <ig:XamGrid Name="ugSearch" Grid.Row="0" Grid.Column="2" AutoGenerateColumns="False" VerticalAlignment="Stretch" HorizontalAlignment="Stretch">
            <ig:XamGrid.SelectionSettings>
                <ig:SelectionSettings />
            </ig:XamGrid.SelectionSettings>
            <ig:XamGrid.EditingSettings>
                <ig:EditingSettings AllowEditing="Row" IsEnterKeyEditingEnabled="True" IsOnCellActiveEditingEnabled="True" IsMouseActionEditingEnabled="SingleClick" />
            </ig:XamGrid.EditingSettings>
            <ig:XamGrid.DeferredScrollingSettings>
                <ig:DeferredScrollingSettings AllowDeferredScrolling="None" />
            </ig:XamGrid.DeferredScrollingSettings>
            <ig:XamGrid.FilteringSettings>
                <ig:FilteringSettings AllowFiltering="FilterRowTop" AllowFilterRow="Top" FilteringScope="ColumnLayout" IsEnterKeyEditingEnabled="True" IsMouseActionEditingEnabled="SingleClick" />
            </ig:XamGrid.FilteringSettings>
            <ig:XamGrid.RowSelectorSettings>
                <ig:RowSelectorSettings EnableRowNumbering="False" />
            </ig:XamGrid.RowSelectorSettings>
            <ig:XamGrid.Columns>
                <ig:TemplateColumn Key="IsSelected" HeaderText=" " HorizontalContentAlignment="Center" HeaderTextHorizontalAlignment="Center" IsFilterable="False" Width="25" IsGroupable="False" IsHideable="False" IsMovable="False" IsSortable="False" IsSummable="False" IsFixable="False">
                    <ig:TemplateColumn.ItemTemplate>
                        <DataTemplate>
                            <CheckBox IsChecked="{Binding IsSelected, Mode=TwoWay}" />
                        </DataTemplate>
                    </ig:TemplateColumn.ItemTemplate>
                </ig:TemplateColumn >
                <ig:TextColumn Key="FileName" HeaderText="Name" Width="120" IsReadOnly="True"></ig:TextColumn>
                <ig:TextColumn Key="Number" HeaderText="#" Width="50" IsReadOnly="True"></ig:TextColumn>
                <ig:TextColumn Key="Title" HeaderText="Heading/Title" Width="120" IsReadOnly="True"></ig:TextColumn>
                <ig:TextColumn Key="Description" HeaderText="Description" Width="120" IsReadOnly="True"></ig:TextColumn>
                <ig:TextColumn Key="FileSizeInMegabytes" HeaderText="Size (MB)" Width="60" HorizontalContentAlignment="Right" IsReadOnly="True"></ig:TextColumn>
                <ig:TextColumn Key="FileType" HeaderText="Type" Width="60" IsReadOnly="True"></ig:TextColumn>
                <ig:TextColumn Key="CheckedOutToName" HeaderText="Checked Out By" Width="120" IsReadOnly="True"></ig:TextColumn>
                <ig:TextColumn Key="UploadDate" HeaderText="Uploaded / Modified" Width="150" IsReadOnly="True"></ig:TextColumn>
            </ig:XamGrid.Columns>