Here's a few steps I gone through.
1. I've installed the latest update to Dreamweaver CS5.5 (Mac).
2. I've signed into CS Live through Dreamweaver.
3 .When I click 'Preview' it loads up the Adobe Labs sign in page. I sign in my password.
4. It then loads the Adobe Labs page with a DreamwaeverConnection Error: ArgumentError: Error #2082
5. When I type a URL into the URL bar click 'Test' it says I don't have any browser sets defined. I've tried adding a browser set but it won't let me. In the top right of the page it says 'Sign Out'.
6. I've also tried deleting the cheychain.
Please can you help. It used to work a while back.