[Mono-list] assembly loaded at runtime and object instance creation

[LordPhoenix]

Hi all,

I'm trying to create object from an assembly wich I'm loading at
runtime. Here is code I'm using: 

In my loaded assembly : 

using System;

namespace test{

    public class Plugin{
        public Plugin(){}
        public void MethodeTest(){
            Console.WriteLine("Appel de la méthode de test");
        }
    }
}

compiled as a library of course.

and in my main program wich must load assembly

using System;
using System.Reflection;

namespace test{
    class Loader{
        public Loader(){
            Assembly ass = Assembly.LoadFrom("plugin.dll");
            Console.WriteLine(ass.FullName);
            System.Object obj = ass.CreateInstance("Plugin",false);
            if(obj==null)
                Console.WriteLine("fail");
            else
                Console.WriteLine("OK");
        }
        public static void Main (string[] args){
            new Loader();
        }
    }
}

and the output is always "fail".

How can do this? What did I miss? 

Thanks for help.

PS Sorry for my bad English I don't speak it very often.