Altious,
Thanks for the login info. We just tested a bit on your site, and plan to continue. The main issue we're running into is that we're seeing a "OAuth Failure" warning on the Login/Registration page. We turned on "Display Facebook API Errors on Front-End" to see that error. Can you test logging in now, and see if you get the same error? If so, that's where the problem is coming from.. basically, there's not connection between your site and Facebook to get the user's information.
Please test it out and see if you get that error, or something else on the registration page. In general, at the top, it should say "Welcome <yourname>!", but right now it's just "Welcome !", which indicates the bad communication.
We're looking into the OAuth 2.0 error that's appearing. It crops up periodically and can be either because your application is still new (in Facebook's eyes) or a caching problem with the browser not storing the session cookie properly. If it's experienced in multiple places, it indicates more of a configuration issue though.
Finally, can you check the following setting sin your Facebook application:
Mobile Tab - Application is set as "HTML5/mobile web" NOT "native"
In the Advanced Tab - All settings are disabled
In advanced, there are a few that can be disabled, but for now, try with all disabled and see what happens.
Let us know what you find, and we'll investigate if there's anything we can do on our end about the OAuth error. Again, if you're not having that error, let us know so we can focus somewhere else.. it may just be a transient issue.
Thanks