Problem with reading data from a combobox in asp .net mvc

I have a asp .net mvc 3 web application. In one of its views I try to populate a couple of comboboxes. When I load the view, there doesn't appear to be a problem, until I try to read the data then I get the following 'The ViewData item that has the key 'GenderID' is of type 'System.Int32' but must be of type 'IEnumerable'

I've been populating the comboboxes using a method I have successfully used in other views, where it works like a charm, so I'm at a loss where I have my problem at the moment.

Here is how I fill the data in the controller:

        var listGenders = ListGenders();         var dropDownGenders = new SelectList(listAgencies, "ID", "Name", 1);
        ViewData["Genders"] = dropDownGenders;

In the view:

   Gender
   <%= Html.DropDownListFor(model => model.GenderID, ViewData["Genders"] as IEnumerable)%>

Does anyone here have an idea?