[jQuery] (Validate) Validation is only occuring the first time "Submit" is clicked

[bcbounders]

I've got weird behavior on the contact form at this address:
http://tinyurl.com/myy8gp'

The initial validation works (i.e. leave all fields blank and click
submit).  If you then enter anything valid into any one of the
required fields and click submit again, the jQuery validation doesn't
seem to occur again (or, if it does, it passes everything even though
other required fields are not valid) and it passes everything to the
PHP file for processing.

Here is the code for the form:
<form id="contactForm" method="post" action="contact-us_assets/contact-
us.php">
        <fieldset>
                <p>
                        <label for="contactName">Name: <span 
class="reqField">*</span><span
class="error reqField"></span></label>
                        <input class="text" size="45" id="contactName" 
name="contactName" /
>
                </p>
                <p>
                        <label for="contactEmail">Email: <span 
class="reqField">*</
span><span class="error reqField"></span></label>
                        <input class="text" size="45" id="contactEmail"
name="contactEmail" />
                </p>
                <p>
                        <label for="contactPhone">Phone:</label>
                        <input class="text" type="text" size="25" 
name="contactPhone"
id="contactPhone" />
                </p>
                <p>
                        <label for="contactCompany">Company:</label>
                        <input class="text" size="45" name="contactCompany"
id="contactCompany" />
                </p>
                <p>
                        <label for="subject">Subject:</label>
                        <input class="text" type="text" size="25" name="subject"
id="subject" />
                </p>
                        <label for="message">Message: <span 
class="reqField">*</span><span
class="error reqField"></span></label>
                        <textarea class="text" cols="50" rows="5" name="message"
id="message"></textarea>
                </p>
                <p>
                        <input class="submit" type="submit" name="submit" 
value="Submit" /
>&nbsp;&nbsp;<input class="reset" type="reset" name="reset"
value="Reset" />
                        <span class="footNote reqField">*Required Fields</span>
                </p>
        </fieldset>
</form>

And here is the jQuery code for the Validation Plugin:

$(document).ready(function() {
        // validate contact form on keyup and submit
        $("#contactForm").validate({
                rules: {
                        contactName: {
                                required: true,
                                minlength: 2
                        },
                        contactEmail: {
                                required: true,
                                email: true
                        },
                        message: {
                                required: true,
                                minlength: 2
                        }
                },
                messages: {
                        contactName: "Please enter your name (2 character 
minimum)",
                        contactEmail: "Please enter a valid email address",
                        message: "Please enter your message (2 character 
minimum)"
                },
                errorPlacement: function(error, element) {
                        element.siblings("label").children("span.error").html(" 
 " +
error.text());
                },
                success: function(error, element){
                        
element.siblings("label").children("span.error").text("");
                }
        });
});

I appreciate any insight into what could be going wrong, as I'm
stumped.

Thanks a lot!

  - John