I am using the JQuery form plugin (http://malsup.com/jquery/form/) to handle the ajax submission of a form. I also have JQuery.Validate (http://docs.jquery.com/Plugins/Validatio
... well it's been a while so my situation has changed a little. Currently I have a submitHandler option passed to the Validate() plugin. In that handler I manually use ajaxSubmit. More a workaround than an answer I guess. Hope that helps.
http://jquery.bassistance.de/validate/demo/ajaxSubmit-intergration-demo.html
var v = jQuery("#form").validate({
submitHandler: function(form) {
jQuery(form).ajaxSubmit({target: "#result"});
}
});