In Dreamweaver, you can create a template to use a design for the pages in your site.
you can use CSS Sculptor to create your layout, then save the CSS Sculptor layout as a template in Dreamweaver. In the data assist wizard, you can select to use the template you created.
see the "Creating and applying a Dreamweaver Template" tutorial on the learning resources page:
The data assist wizard is not re entrant, if you need to add or delete a filed from the database, you will either need to manually edit the server behaviors on the pages, or delete them and re run the wizard.
It sounds to me like your style changes are not being saved and uploaded to the server.