Returning .Net objects to VFP via COM Interop.

It looks like it works but the problem is:

LOCAL lo as "MyInterop.MyComm", ds
lo = CREATEOBJECT("MyInterop.MyComm")
ds = lo.GetDataset("HumanResources.Department")
? ds.ToString() && "System.Data.DataSet"
? type('ds.Tables') && Object
? ds.Tables.Count && error
? ds.Tables.Item(0).Rows.Item(0).Item(1) && error

* this works and I get the result
XMLTOCURSOR(ds.GetXML,'result') 
browse

Neither ds.Tables.Item(0)... nor ds.Tables(0)... work. Any idea?

Here is the very simplified version of .Net code:

using System;
using System.Collections.Generic;
using System.Runtime.InteropServices;
using System.Text;
using System.Data;
using System.Data.Sql;
using System.Data.SqlClient;

namespace MyInterop
{
    [ClassInterface(ClassInterfaceType.AutoDual)]
    [ProgId("MyInterop.MyComm")]
    [ComVisible(true)]
    public class MyComm
    {
        public DataSet GetDataset(string tableName)
        {
            DataSet ds = new DataSet();
            SqlConnection con = 
               new SqlConnection("server=.\\sqlexpress;database=AdventureWorks;Trusted_connection=yes");
            SqlDataAdapter adp = new SqlDataAdapter(String.Format("select * from {0}", tableName), con);
            adp.Fill(ds);

            return ds;
        }
    }
}

Thanks in advance.
Cetin