[WPF] ListView: SelectedItems ritorna sempre 1 elemento

[robertino_salemi]

Buonasera,
sto utilizzando la ListView

<ListView x:Name="chkListViewSampleStatus" HorizontalAlignment="Left" VerticalAlignment="Top"               
	DataContext="{StaticResource DomainDataViewModel}" ItemsSource="{Binding SampleStatus}" IsSynchronizedWithCurrentItem="True" Width="727" Height="50">
	<ListView.ItemsPanel>
		<ItemsPanelTemplate>
			<WrapPanel Width="{Binding (FrameworkElement.ActualWidth), RelativeSource={RelativeSource AncestorType=ScrollContentPresenter}}"
			   ItemWidth="{Binding (ListView.View).ItemWidth, RelativeSource={RelativeSource AncestorType=ListView}}"
			   MinWidth="{Binding ItemWidth, RelativeSource={RelativeSource Self}}"
			   ItemHeight="{Binding (ListView.View).ItemHeight, RelativeSource={RelativeSource AncestorType=ListView}}" />
		</ItemsPanelTemplate>
	</ListView.ItemsPanel>
	<ListView.View>
		<GridView ColumnHeaderContainerStyle="{StaticResource myHeaderStyle}">
			<GridView.Columns>
				<GridViewColumn Width="20">
					<GridViewColumn.CellTemplate>
						<DataTemplate>
							<CheckBox Tag="{Binding Name}" HorizontalContentAlignment="Stretch" Margin="-5" Padding="-5"/>
						</DataTemplate>
					</GridViewColumn.CellTemplate>
				</GridViewColumn>
				<GridViewColumn DisplayMemberBinding="{Binding ValueDescription}" Width="110" />
			</GridView.Columns>
		</GridView>
	</ListView.View>
</ListView>

Vedo i miei elementi composti da label + checkbox, seleziono 2 o più elementi, ma (nel code behind) se provo a vedere gli elementi selezionati:

chkListViewSampleStatus.SelectedItems

Vedo sempre e solo 1 elemento.

Perchè?

Grazie.