I think the issue is still that you had to adjust the security settings to connect with the browser, and you can't adjust the same settings in Dreamweaver, so it can't connect. I'm not an IT guy, I just know how dreamweaver works, so unfortunately I can only point out what the problem is and not how to solve it.
You seem to be doing some unique things with your network that I haven't run into before.
Are you eventually uploading to a live site? What about using a sub-directory of the live site for testing instead of localhost? That might be easier to configure properly at this point.