any time you add a new column to the eCart object, you will need to update the add to cart buttons on the product detail page. to do this, double click the add to cart from recordset server behavior in the server behaviors list, On the bindings panel, you will need to bind the new eCart column to the correct value.
after updating the product detail page, you will need to upload the product detail file and the WA_eCart folder to the server for.
The content management information is stored in the database, when you sync the site in Dreamweaver, you are only syncing the site files not the database information. you would need to export the remote database, then import it into the local database for the two to be the same.