You look to have multiple extensions trying to handle Facebook integration on your site. Facebook can only communicate with one extension, so you'll need to disable the others. Additionally, with 4.0, we updated our authentication to handle a new Cookie format, required by Facebook in October. The other extensions are telling Facebook to still use the old format, which is likely why the auto-login isn't working (we can't read the old cookie, so we can't detect that they're logged in).
When looking at the source of your page, you should only see one reference to an "all.js" file, which is the Facebook library. Currently, there are 3. One is JomSocial. I'm not sure what the other is. To properly integration JFBConnect with JomSocial, see:
www.sourcecoast.com/jfbconnect/docs/thir...ration-for-jomsocial
You'll have to determine what the other Facebook extension is doing. Should you need help, just let us know.
Good luck,
Alex