UPDATE 5/12/11: This issue has been resolved and Facebook registration has been re-enabled. Thank you for your patience!
We’ve temporarily disabled the option to create a new account on FontShop.com with your Facebook account. This prevents a redirect loop which is being caused by a bug on Facebook’s side. Customers who have previously created accounts with Facebook are still able to log in. You may still create a new account by completing the “Create an account” fields on our registration page. Should you choose to sync this with your Facebook account in the future, you can do so automatically once the bug is fixed (provided your email is the same as the one associated with your Facebook account).
Thank you for your patience. We will restore things back to normal once a fix comes through from Facebook.