iOS and Facebook Graph API: Inconsistent authorize issues

I'm using the official FBConnect library for iOS and trying to get it working in my iPad app. Here's what's strange: when my friend logs in using the call to authorize:permissions:delegate, everything works fine: the dialog asks for his authorization to connect to Facebook, the fbDidLogin delegate method gets called, all is well.

However, when I try to login, the dialog never changes. The keyboard is dismissed, the password field is cleared and it just sits there. The issue is the same in both the simulator and on the device.

Here are the things I've checked and triple checked:

• My login name and password are correct. If I do put in the wrong password, an "invalid username/password" message appears, and that isn't happening.
• The application is not in sandbox mode.
• The Application ID is correct (my friend can login without problems).

Some additional information:

• Original application was created by my friend.
• I created a second FB app and put in the new Application ID
• My friend can login with the new Application ID
• I can log in to neither.

This appears to suggest that there is something different about my friend's account, rather than the app itself.

We've been banging our heads together on this for a couple of开发者_开发知识库 days now. What could be causing this behaviour? Why isn't an error being generated?

Edit: It seems there are a lot of people affected by this, so in the interest of trying to find an answer, I've added a bounty.

There appears to be a server-side problem with Facebook logins as noted here:

http://github.com/facebook/facebook-ios-sdk/issues#issue/95

People have said that if they change their password on Facebook they are subsequently able to log in using the Facebook-iOS-SDK downloaded from github. Obviously that is a poor long-term solution and would be unacceptable in an app released through the App Store. On the bright side, there seem to be reports of similar login problems logging in from apps on other platforms as well.

Update: Facebook has a bug filed on this subject that can be viewed here:

http://bugs.developers.facebook.net/show_bug.cgi?id=13199