[nem-en] strange error message from ncc

[NoiseEHC]

using System;
using System.Text;
using Nemerle.Imperative;

//#endregion

namespace Application
{
  class Program
  {
    static Main (args : array [string]) : void
    {
      //Console.WriteLine("Hello");
      while(true) {
      }
      //when(true) {
      //}
      if(true) {
      } else {
      }
    }
  }
}

this program generates:

        C:\Program Files\Nemerle\ncc.exe /no-color /define:DEBUG;TRACE 
/debug+ /out:obj\Debug\Application.exe /target:exe Program.n AssemblyInfo.n
Program.n(13,18): Warning: N168: a function parameter args was never used
Program.n(20,7): Warning: this expression has been skipped in code 
generation due to throw usage
Program.n(20,7): Warning: (() :> void)
        Project6 -> C:\Documents and Settings\Administrator\My 
Documents\Visual Studio 
2005\Projects\Project6\Project6\bin\Debug\Application.exe

but only if while(true) {} is not commented out...

???