when adding the standard "no white space" method to a field, the field will be marked as invalid when entering a white space, but when removing the white space the field does not get re-validated again (or at least fails to return to a valid state).

      $.validator.addMethod("nowhitespace", function(value, element) {
      	return this.optional(element) || /^S+$/i.test(value);
      }, "No white space please"); 

      $('#myform').validate({
        rules: {
          field: {
            nowhitespace: true
          }
}});