Double tap gesture

The following code does nothing when I tap twice. Doesn't matter how fast I tap. However, when I change the number of taps required to 1, it works fine... I'm on the latest pre1 of forms...

    var imgLogo = new Image { Source = ImageSource.FromFile("login") };
                imgLogo.GestureRecognizers.Add(new TapGestureRecognizer
                {
                    Command = new Command(() =>
                    {
                        // Handle taps
                    }),
                    NumberOfTapsRequired = 2
                });
                slMain.Children.Add(imgLogo);