[DotGNU]System.IO.Directory compile error

[j_post]

Perhaps I've gone brain-dead, but I don't understand why I get this compiler 
error. Any help appreciated.
TIA,
Jeff

// compiled with "cscc -lSystem -o dir.exe dir.cs
// gives error "called object is not a method or delegate"

using System;
using System.IO;
using System.IO.Directory;

namespace DIRECTORYTEST
{
        class MainClass
        {
                static int Main(string[] args)
                {
                        string thisDir = 
System.IO.Directory.GetCurrentDirectory();
// error with GetCurrentDirectory() - not method or delegate
                        Console.WriteLine("Current directory: {0}", thisDir);
                        return 0;
                }
        }
}