Ribbon Tab that supports ICheckableCommandParameter

<apribbon:RibbonTab x:Name="MyRibbon">
  <apribbon:RibbonTab.CommandParameter>
    <apribbon:CheckableCommandParameter IsChecked="{Binding ElementName=MyRibbon, Path=IsChecked, Mode=OneWayToSource}" />
  </apribbon:RibbonTab.CommandParameter> 
  ...
</apribbon:RibbonTab>

public class CustomCheckableCommandParameter : DependencyObject, ICheckableCommandParameter
    {
        #region Fields

        public static readonly DependencyProperty IsCheckedProperty;
        public static readonly DependencyProperty HandledProperty;
        public static readonly DependencyProperty TagProperty;

        #endregion Fields

        #region Properties

        public bool? IsChecked
        {
            get { return (bool)GetValue(IsCheckedProperty); }
            set { SetValue(IsCheckedProperty, value); }
        }

        public bool Handled
        {
            get { return (bool)GetValue(HandledProperty); }
            set { SetValue(HandledProperty, value); }
        }

        public object Tag
        {
            get { return (object)GetValue(TagProperty); }
            set { SetValue(TagProperty, value); }
        }


        #endregion Properties

        #region Events

        public event EventHandler IsCheckedChanged;

        #endregion Events

        static CustomCheckableCommandParameter()
        {
            IsCheckedProperty =
                DependencyProperty.Register(
                "IsChecked",
                typeof(bool),
                typeof(CustomCheckableCommandParameter),
                new PropertyMetadata(false, new PropertyChangedCallback(OnCheckedChanged)));

            HandledProperty =
                DependencyProperty.Register(
                "Handled",
                typeof(bool),
                typeof(CustomCheckableCommandParameter),
                new PropertyMetadata(false));

            TagProperty =
                DependencyProperty.Register(
                "Tag",
                typeof(object),
                typeof(CustomCheckableCommandParameter),
                new PropertyMetadata((object)null));
        }


        public CustomCheckableCommandParameter()
            : base()
        {
        }

        private static void OnCheckedChanged(DependencyObject d, DependencyPropertyChangedEventArgs e)
        {
            CustomCheckableCommandParameter checkableParameter = (CustomCheckableCommandParameter)d;
            checkableParameter.OnIsCheckedChanged();
        }

        protected virtual void OnIsCheckedChanged()
        {
            if (IsCheckedChanged != null)
            {
                IsCheckedChanged(this, EventArgs.Empty);
            }

        }
    }

public class CustomRibbonTab : ActiproSoftware.Windows.Controls.Ribbon.Controls.Tab
    {
        public CustomRibbonTab()
            : base()
        {
        }

        protected override void OnPropertyChanged(DependencyPropertyChangedEventArgs e)
        {
            if (e.Property == CommandParameterProperty)
            {
                HookUpIsChecked();
            }

            base.OnPropertyChanged(e);
        }
        
        private void HookUpIsChecked()
        {
            var param = CommandParameter as CustomCheckableCommandParameter;

            if (null != param)
            {
                param.IsCheckedChanged += delegate
                {
                    if (param.IsChecked == true)
                    {
                        var ribbon = UIHelper.FindAncestor(this, typeof(Ribbon)) as Ribbon;
                        if (null != ribbon)
                        {
                            ribbon.SelectedTab = this; //in this way I'm selecting the right tab
                            //this.IsChecked = true; // this line doesn't select the right tab
                        }
                    }
                };
            }
        }       
    }

 <!-- "Suppliers" Tab -->
<p:CustomRibbonTab Label="Suppliers" Command="NavigationCommands.GoToPage" CommandTarget="{Binding ElementName=local, Path=TargetContentContainer}">
<p:CustomRibbonTab.CommandParameter>
    <p:CustomCheckableCommandParameter Tag="{x:Type p:SuppliersListPage}"/>
</p:CustomRibbonTab.CommandParameter>
</p:CustomRibbonTab>

ribbon.SelectedTab = this

<apribbon:RibbonTab x:Name="MyRibbonTab">
  <apribbon:RibbonTab.CommandParameter>
    <apribbon:CheckableCommandParameter IsChecked="{Binding ElementName=MyRibbonTab, Path=(Selector.IsSelected), Mode=OneWayToSource}" />
  </apribbon:RibbonTab.CommandParameter> 
  ...
</apribbon:RibbonTab>