Wpf Command not firing

I used already Command Binding in my XAML but strangely this specififc one doesn't work. Did i miss something?

Class for Commands:

public class VMCommand : ICommand
{
    public delegate void ICommandOnExecute(object parameter);
    public delegate bool ICommandOnCanExecute(object parameter);

    private ICommandOnExecute _execute;
    private ICommandOnCanExecute _canExecute;

    public VMCommand(Action exec, bool canExec)
    {
        _execute = delegate(object param) { exec(); };
        _canExecute = delegate(object param) { return canExec; };
    }

    public VMCommand(Action<object> exec, bool canExec)
    {
        _execute = delegate(object param) { exec(param); };
        _canExecute = delegate(object param) { return canExec; };
    }

    #region ICommand Members

    public event EventHandler CanExecuteChanged
    {
        add { CommandManager.RequerySuggested += value; }
        remove { CommandManager.RequerySuggested -= value; }
    }

    public bool CanExecute(object parameter)
    {
        return _canExecute.Invoke(parameter);
    }

    public void Execute(object parameter)
    {
        _execute.Invoke(parameter);
    }

    #endregion
}

Xaml:

<ListBox DataContext="{DynamicResource Client}" ItemsSource="{Binding Players}" Background="{StaticResource BrushDark}" HorizontalContentAlignment="Stretch">
                        <ListBox.ItemTemplate>
                            <DataTemplate>
                                <Grid>
                                    <Grid.ColumnDefinitions>
                                        <ColumnDefinition Width="1*"/>
                                        <ColumnDefinition Width="1*"/>
                                        <ColumnDefinition Width="1*"/>
                                        <ColumnDefinition Width="1*"/>
                                    </Grid.ColumnDefinitions>
                                    <Grid.RowDefinitions>
                                        <RowDefinition Height="1*"/>
                                        <RowDefinition Height="1*"/>
                                    </Grid.RowDefinitions>
                                    <TextBlock Text="{Binding Name}" Foreground="{StaticResource BrushTextNormal}" Grid.Column="0" Grid.Row="0"/>
                                    <TextBlock Text="{Binding KillsZombies}" Foreground="{StaticResource BrushTextNormal}" Grid.Column="1" Grid.Row="0"/>
                                    <TextBlock Text="{Binding Score}" Foreground="{StaticResource BrushTextNormal}" Grid.Column="2" Grid.Row="0"/>
                                    <TextBlock Text="{Binding Ping}" Foreground="{StaticResource BrushTextNormal}" Grid.Column="3" Grid.Row="0"/>
                                    <StackPanel Orientation="Horizontal" Grid.Column="0" Grid.ColumnSpan="4" Grid.Row="1" Name="Actions" Visibility="Collapsed">
                                        <Button Content="Kick" Style="{StaticResource Button}" Margin="20,5,0,0" Width="50" Height="25" DataContext="{DynamicResource Client}" Command="{Binding Test}"/>
                                        <!--{x:Static local:VMServer+PlayerCommand.KICK}-->
                                        <Button Content="Ban" Style="{StaticResource Button}" Margin="20,5,0,0" Width="50" Height="25" Command="{Binding Test}"/>
                                    </StackPanel>
                                </Grid>
                                <DataTemplate.Triggers>
                                    <DataTrigger Binding="{Binding RelativeSource={RelativeSource Mode=FindAncestor, AncestorType={x:Type ListBoxItem}}, Path=IsSelected}" Value="True">
                                        <Setter Property="Visibility" Value="Visible" TargetName="Actions"/>
                                    </DataTrigger>
                                    <DataTrigger Binding="{Binding RelativeSource={RelativeSource Mode=FindAncestor, AncestorType={x:Type ListBoxItem}}, Path=IsFocused}" Value="False">
                                        <Setter Property="Visibility" Value="Collapsed" TargetName="Actions"/>
                                    </DataTrigger>
                                </DataTemplate.Triggers>
                            </DataTemplate>
                        </ListBox.ItemTemplate>
                    </ListBox>

Whereas in my VM:

private VMCommand _test;
    public VMCommand Test
    {
        get
        {
            Action a = new Action(delegate()
            {
                MessageBox.Show("yay");
            });
            return new VMCommand(a, true);
        }
    }

In this case Client is my Viemodel here containing all the needed things.

Outside the listbox command binding seems to work like a charm (got a connect button with binding, works perfectly), but the buttons inside the Stackpanel wont fire any event at any time.

Did I miss something?