As Scott pointed out, not all hosts require a public_html, have you tried leaving that field blank?
http://wiki.dreamhost.com/Uploading_your_site
Yahoo required a blank remote folder field. There was an index.html file on the server to be overwritten by the user's index file.
Also, VSD previews don't display some scripts (like FB widgets, Twitter buttons). So if you don't see your social buttons, or you see some text instead of the buttons – not to worry. They show up on the live site.