Entonces obligados estamos a poner en el form_unload() set form = nothing ? que feo eso de vb6.. jaja

Form Modules
Form modules, like class modules, require that an instance of the form be created before its code and data can be used. However, VB treats form modules somewhat differently and will automatically create an instance of a form if any propery of the form is referenced in your code. Also remember that module level variables in forms are not destroyed until the reference to the form object is released by setting the form to Nothing. Unloading a form does not clear the value of the form's module level variables.