I have a treeview which contains files, every view model holds an item source which is an ObservableCollection with files items: public ObservableCollection<CMItemFileNode> SubItemNode On each item i have context menu options (Delete, Execute..). If i move from one viewModel to another the ObservableCollection of files updated correctly and presented correctly but, when i perform a context menu command like delete file item, the command execute good but when i move to another view model (which holds SubItemNode ObservableCollection of is own) after the command executed the WPF still thinks i'm in the last view model i was in and not the one i'm really on. Very important to mention is that when i update to .net 4.5 (which unfortunantly i can't do) everything is ok and the ObservableCollection addresses the correct view model. Here is the treeView: <TreeView x:Name="Files" Margin="0,5,5,0" Grid.Row="6" Grid.Column="2" ItemsSource="{Binding SubItemNode}" HorizontalAlignment="Stretch" HorizontalContentAlignment="Stretch" VerticalAlignment="Stretch" Height="300" Grid.RowSpan="6" Width="300" dd:DragDrop.IsDragSource="True" dd:DragDrop.IsDropTarget="True" dd:DragDrop.DropHandler="{Binding}" dd:DragDrop.UseDefaultDragAdorner="True"> <TreeView.Resources> <Style TargetType="{x:Type TreeView}"> <Setter Property="local:CMTreeViewFilesBehavior.IsTreeViewFilesBehavior" Value="True"/> </Style> <Style TargetType="{x:Type TreeViewItem}"> <Setter Property="IsSelected" Value="{Binding IsSelected}" /> <Setter Property="local:CMTreeViewFilesItemBehavior.IsTreeViewFilesItemBehavior" Value="True"/> </Style> <SolidColorBrush x:Key="{x:Static SystemColors.HighlightBrushKey}" Color="Transparent" /> <SolidColorBrush x:Key="{x:Static SystemColors.HighlightTextBrushKey}" Color="Black" /> </TreeView.Resources> <TreeView.ContextMenu> <ContextMenu> <MenuItem Header="View File" Command="{Binding ExecuteFileCommand}" /> <Separator /> <MenuItem Header="Delete all" Command="{Binding DeleteAllFilesCommand}" /> <MenuItem Header="Delete selected" Command="{Binding DeleteSelectedFilesCommand}" /> </ContextMenu> </TreeView.ContextMenu> <TreeView.ItemTemplate> <HierarchicalDataTemplate ItemsSource="{Binding SubItemNode}" > <Grid> <Grid.ColumnDefinitions> <ColumnDefinition Width="Auto"/> <ColumnDefinition Width="*"/> </Grid.ColumnDefinitions> <Image Grid.Column="0" Margin="2" Width="32" Height="18" Source="{Binding Path=Icon}" HorizontalAlignment="Left" VerticalAlignment="Center" /> <TextBlock Text="{Binding Path=Name}" Grid.Column="1" Margin="2" VerticalAlignment="Center" Foreground="{Binding Path=Status, Converter={StaticResource ItemFileStatusToColor}}" FontWeight="{Binding Path=IsSelected, Converter={StaticResource BoolToFontWidth}}"/> </Grid> </HierarchicalDataTemplate> </TreeView.ItemTemplate> </TreeView> Am I doing somthing wrong? and why in .net 4.5 it works well ?