C sharp - pase de parametros stored mysql con c#

ERROR:
"Parameter '?clogin' is not found but a parameter with the name 'clogin' is found. Parameter names must include the leading parameter marker."

sp

CREATE DEFINER=`root`@`localhost` PROCEDURE `spadmusers`(IN clogin varchar(50),IN cpassword varchar(50))
BEGIN
select * from ut_users where slogin=clogin and spassword=cpassword;
END$$

codigo .net (c#)

string cad= "Database=saga;Data Source=localhost;User Id=root;Password=123456";
MySqlConnection cnn=new MySqlConnection(cad);
cnn.Open();
MySqlCommand comando=new MySqlCommand();
comando.Connection = cnn;
comando.CommandType = CommandType.StoredProcedure;
comando.CommandText = "spadmusers";
MySqlParameter p=new MySqlParameter("clogin", MySqlDbType.VarChar);
p.Value = this.login;
comando.Parameters.Add(p);
MySqlParameter p2 = new MySqlParameter("cpassword", MySqlDbType.VarChar);
p2.Value = this.password;
comando.Parameters.Add(p2);
MySqlDataAdapter DAdapter= new MySqlDataAdapter();
DAdapter.SelectCommand = comando;
DataSet ds = new DataSet();
DAdapter.Fill(ds);

Agradezco cualquier ayuda, ya no encuentro que hacer. Muchas gracias.