I have had problems instanciating classes that have empty constructors defined. (PHP 4.05, win2000)

if a class has a constructor defined it seems that a (any) variable of that class must be set inside the constructor ot the class does not become properly instanciated. 
If there is no Constructor then this problem does not exist.

eg1, this works:
  class Foo   
  {
    var $a;

    function Foo()
    {
      $a = 1;
    }
  }

eg2, this does not work

  class Foo   
  {
    var $a;

    function Foo()
    {
      //empty constructor
    }
  }

eg3, this works

class Foo   
  {
    var $a;

    //no constructor defined

  }