dont preview in DW, rather upload to a server, i suppose you are using PHP? if you are using php and dont have a local server to post to you could use something like wamp
Install PHP 5 Apache MySQL on Windows : WampServer and then you could just save directly to the wamp directory and then view it instantly in your localhost session.
As i have precious little knowledge about dreamweaver, or any other wysiwyg, as i never use them i hope this helps.
:)