Facebook requires every site to switch to OAuth 2.0 and no later than October. I have updated my most appreciated masterpiece. Current version is 5.0.4b, download is available here.
The add-on is rewritten completely (hell, the old structure is a mess, hahah). Actually I don't plan to update this anymore but the guy from Zynga contacted me a week ago and asked if I can help him move the Zynga forums to OAuth 2.0. He contacted me a few times before and I offered to lend him a helping hand and it was a pleasure assist him and Zynga's community. I always try my best and on this occasion the outcome was great. You can now head over to http://forums.zynga.com/ and click the Connect to Facebook link, I hope it works for everyone out there.