sdh100shaun

I did a similiar thing in a plugin prior to 3.0 i.e. not with custom post types but as your tag suggests used ajax

I used jQuery with a ajax request like this
$.post(url, { action:"uon_post","cookie": encodeURIComponent(document.cookie),postId: $('#post_ID').val() ,"storytype":storytype,"ImgPath":imgPath },

and the recieving plugin function /action like this

add_action('wp_ajax_uon_post', 'postManagementajaxCall');
function postManagementajaxCall()
	{

		$return="";

		if(isset($_POST))
		{
			$filters = array
		  (
		  "postId" => FILTER_VALIDATE_INT,
		  "storytype" => FILTER_SANITIZE_STRING,
		  "ImgPath"=> FILTER_SANITIZE_STRING
		  );

			$args=filter_var_array($_POST, $filters);

			global $wpdb; 

			$postManagement= new PostManagement($wpdb);

			echo $postManagement->processPost($args["postId"],$args["storytype"],$args["ImgPath"]); 

			exit();
		}
	}

The key things to note are the action name in both the jquery/javascript and php

Hope that helps along the way a bit – feel free to ask for clarification (happy to help if I can) @sdh100shaun