Call To Stored Proc Returning Null Datatable

I have a stored proc which should be returning a datatable.  When I execute it manually it returns all requested results. However, when I call it via code (C#) it is returning a null table which leads me to believe the problem is in my code.  I'm not getting any errors during runtime.  Any help at all would be a BIG help!

private void PopulateControls()
    {
        DataTable table = CartAccess.getCart();
    }

public static DataTable getCart()
 {
        DbCommand comm = GenericDataAccess.CreateCommand();
        comm.CommandText = "sp_cartGetCart";

        DbParameter param = comm.CreateParameter();
        param.ParameterName = "@CartID";
        param.Value = cartID;
        param.DbType = DbType.String;
        param.Size = 36;
        comm.Parameters.Add(param);

        DataTable table = (GenericDataAccess.ExecuteSelectCommand(comm));
        return table;
 }


public static DataTable ExecuteSelectCommand(DbCommand command)
    {
        // The DataTable to be returned
        DataTable table;
        // Execute the command making sure the connection gets closed in the end
        try
        {
            // Open the data connection
            command.Connection.Open();
            // Execute the command and save the results in a DataTable
            DbDataReader reader = command.ExecuteReader();
            table = new DataTable();
            table.Load(reader);
            // Close the reader
            reader.Close();
        }
        catch (Exception ex)
        {
            Utilities.SendErrorLogEmail(ex);
            throw ex;
        }
        finally
        {
            // Close the connection
            command.Connection.Close();
        }
        return table;
    }