Misaligned Tab in Android

Hi

I use TabbedPages to display some tabs. On android it all aligns to left side i.e. It does not take equal space to fill the entire screen width
Screenshot attached

My code is very simple and looks like

public static Page GetMainPage ()
{   
    return new CommonTabbedPage();
}

public class CommonTabbedPage : TabbedPage
    {
        public CommonTabbedPage ()
        {
            this.Children.Add (new ContentPage () { Title = "page 1" });
            this.Children.Add (new ContentPage () { Title = "page 2" });
            this.Children.Add (new ContentPage () { Title = "page 3" });
            this.Children.Add (new ContentPage () { Title = "page 4" });
            this.Children.Add (new ContentPage () { Title = "page 5" });
        }
    }

Am i missing something .... or is this a bug ???