[jQuery] Modal dialog validation problem

[cerberos]

I have a form in a modal dialog which I submit with $.post().
Validation is set so that the name field has a min length of 2.

* enter 'a' in name and submit
* validation works, form not submitted, error displayed
* submit again (still with 'a' for name)
* validation fails, form gets submitted and record is created with
invalid name ('a' - too short)

Any ideas why validation is not being called the second time?

  function addNewPlace(parentID, heading, placeType, fade, remove,
backup){
    $("#addPlace").remove(); // remove any previous forms

    $.get("http://localhost:8000/places/add-place";,
{parent:parentID},function(data){
      $(data).dialog({modal:true, resizable:false, draggable:false,
title:heading, width: 400});
      $("#id_type").val(placeType);

      $("form#addPlace").submit(function(){
        placeName = $("form#addPlace #id_name").val();

        $.post("/places/add-place", $("#addPlace").serialize(),
function(){
          $("#addPlace").dialog('close');
          updateSelect(parentID, fade, remove, backup, placeName)
        });

        return false;
      });

      $("#addPlace").validate({
        rules: {
          name: {
            required: true,
            minlength: 2
          },
        },
        errorElement: "p",
        errorClass: "errorField",
        errorPlacement: function(error, element) {
          error.appendTo( element.parent() );
        },
        highlight: function(element, errorClass) {
          $(element).parent().addClass('error');
        },
        unhighlight: function(element, errorClass) {
          $(element).parent().removeClass('error');
        },
      });
    });
  }