Cannot instantiate object using reflection/Assembly/Activator in c# from a string

I have a namespace that defines a class (I'll omit the code):

namespace My.Business.Services
{
    public class ProgressSender
    {
    }
}

This project is saved as a DLL.

In another project in my solution I try to instatiate it in various ways (in reality this is a string in my app.config) but they all fail (it does work explicitly creating the class early bound in code). I've included My.Business.Services as a reference to the program too:

namespace My.Progress.Imaging
{
  static class Program
  {
    static void Main(string[] args)
    {
        string exportItemNS = "My.Business.Services";
        string exportItemC  = "ProgressSender";
        string exportItemFull = "My.Business.Services.ProgressSender";

        //value cannot be null
        ProgressSender obj =     
         (ProgressSender)Activator.CreateInstance(Type.GetType(exportItemFull));

        //could not load type 'ProgressSender' from assembly 'My.Business.Services'
        var obj=Activator.CreateInstance(exportItemNS, exportItemC);

        //could not load type 'ProgressSender' from assembly 'My.Business.Services'
        ProgressSender s=(ProgressSender)Activator.CreateInstance(null, exportItemFull);

       //Loads ok but then classType is null
        Assembly assembly;
        assembly = Assembly.Load(exportItemNS);
        Type classType = assembly.GetType(exportItemC);

   }
 }
}

If I get a type from the same namespace or even System it's fine:

Type t = Type.GetType("My.Progress.Imaging.Program");
t = Type.GetType("System.String");