I'm trying to use the Html.DropDownListFor<> HtmlHelper and am having a little trouble binding on post. The HTML renders properly but I never get a "selected" value when submitting.

<%= Html.DropDownListFor( m => m.TimeZones, Model.TimeZones, new { @class = "SecureDropDown", name = "SelectedTimeZone" } ) %>

[Bind(Exclude = "TimeZones")]
    public class SettingsViewModel : ProfileBaseModel
    {
        public IEnumerable TimeZones { get; set; }
        public string TimeZone { get; set; }

        public SettingsViewModel()
        {
            TimeZones = GetTimeZones();
            TimeZone = string.Empty;
        }

        private static IEnumerable GetTimeZones()
        {
            var timeZones = TimeZoneInfo.GetSystemTimeZones().ToList();
            return timeZones.Select( t => new SelectListItem { Text = t.DisplayName, Value = t.Id } );
        }
    }

I've tried a few different things and am sure I am doing something stupid... just not sure what it is :)