Question

I have a very strange issue with the jQuery Validation plugin where it won’t validate a select that was pre-filled then modified.

You can look at the code here: http://jsfiddle.net/VwRJ8/1/

The code never fires the alert() in the following lines:

$('#edit_loc_save').click(function() {
    var foo = $('#add_new_loc_form').valid();
    alert(foo);
});

Answer 1

You can check if the select is valid each time the value is changed:

Javascript

$('#myform').validate();
$('#myselectbox').on('change', function() {
    $(this).valid();
});

Demo

Edit 1

Here is what is causing an error in your javascript, which is preventing the validate function to operate correctly:

new_loc_zip: {
    required: true,
    postalcode: true // This is not a correct setting in jquery validate
},

If you remove the postalcode: true line, validate will call properly.

Demo