Hello
I'm trying to use odata as the proxy and getting "Request failture error"
I must be missing something pretty simple, possible with WFC data service ?
In attachment as well screenshot from the whole browser (note that store of combobox is empty)

here is code

Page:

<%@ Page Language="C#" AutoEventWireup="true" CodeFile="Test1.aspx.cs" Inherits="Tests_Test1" %>

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head runat="server">
	<title></title>
</head>
<body>
	<form id="form1" runat="server">
	<div>
		<ext:ResourceManager runat="server" runat="server" Theme="Gray" Namespace="">
		</ext:ResourceManager>
		<ext:ComboBox runat="server">
			<Store>
				<ext:Store runat="server" AutoLoad="true">
					<Proxy>
						<ext:ODataProxy Url="../WcfDataService.svc/LeaderTypes" >
							<Writer>
								<ext:JsonWriter/>
							</Writer>
							<Reader>
								<ext:ODataReader runat="server" />
							</Reader>
						</ext:ODataProxy>
					</Proxy>
				</ext:Store>
			</Store>
		</ext:ComboBox>
	</div>
	</form>
</body>
</html>
service

public class WcfDataService : DataService<AmsDbContext>
{
    // This method is called only once to initialize service-wide policies.
    public static void InitializeService(DataServiceConfiguration config)
    {
        // TODO: set rules to indicate which entity sets and service operations are visible, updatable, etc.
        // Examples:
        // config.SetEntitySetAccessRule("MyEntityset", EntitySetRights.AllRead);
        // config.SetServiceOperationAccessRule("MyServiceOperation", ServiceOperationRights.All);
		config.SetEntitySetAccessRule("*", EntitySetRights.All);
        config.DataServiceBehavior.MaxProtocolVersion = DataServiceProtocolVersion.V2;
    }
}
Firefox + firebug result

Click image for larger version. 

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