jQuer Validation failing unless call $('#form').valid()
===

I have a large application that is using a lot of jQuery and I ran across one page today in testing that will not validate correctly. I have saved a copy of the page off and deleted all other jQuery except the code to validate the single field that I am having trouble with.

In the following code, it works perfectly:

    <script type="text/javascript">
        $(document).ready(function () {
            $('#btnSave').click(function (e) { validateRegisterForm(e); });
        });

        function validateRegisterForm(e) {

            $('#EMasterForm').validate();
            alert('validation result is : '+ $('#EmasterForm').valid());
            $('#txtMaxCommute').rules                 
                ('add', { 
                    required: true, 
                    minlength: 2,
                }); // end of rules(add) function call

                if ($('#EmasterForm').valid() == false) {
                    e.preventDefault();
            }
        }


    </script>

But if I comment out the alert, it does not work. And the alert always shows a value of 'true'.

This seems like a dumb question to me. But I have 50 other pages validating like clockwork. And I am coming up short on this one. We are using jquery everywhere for all sorts of operations. But this one page will not work. 

Can anyone possibly shed any light on why the alert would make it work? I am happy to be chastised by whomever answers this :)

Thank you in advance!