Mobile facebook login not logging in iPhone users?

I've got to be doing something very obvious wrong here, because I just can't bring myself to believe that facebook's mobile login isn't working correctly for iPhone users. If you have a look at these urls, you'll see that they work (after you replace the 'YOUR_APP_ID' and 'YOUR_REDIRECT_URL', of course) in web browsers & Androids, but on iPhones (3s and 4s) they take you right into facebook and you never see the Extended Permissions page or get redirected:

https://graph.facebook.com/oauth/authorize?type=user_agent&client_id=YOUR_APP_ID&redirect_uri=YOUR_REDIRECT_URL&display=wap&scope=email,user_location,read_friendlists,publish_stream,offline_access

https://m.facebook.co开发者_StackOverflow社区m/dialog/oauth?client_id=YOUR_APP_ID&redirect_uri=YOUR_REDIRECT_URL&scope=email,user_location,read_friendlists,publish_stream,offline_access

I mean, I'm sure they tested their mobile login stuff on an iPhone, right? Anyone know what I'm doing wrong?