Apple ID incorrect after IOS 7 update?

My little brother and I have the same Iphones and last night both got updated to the new IOS 7. Mine has had no issues but after trying to set up his phone he gets a message saying his Apple ID password is incorrect. He's used the same one for a year now, even tried the one he used before that and nothing. Is this a glitch because of the update? How can he fix it? Anyone who has a suggestion that would be awesome cause he won't leave me alone until I fix it.

That is my problem too after i install, well i fix it i just reset my netwok in the setting and connect agin in the Wi-Fi. I can log in now.

MS and Mac users have far to much faith in their lord and master. My advice to you would be go and join the Mac users forum their web link is below ask your questions there. How would anyone know anything about iOS7 when it's a totally new system that has only been out for a day

I would plug his phone into the computer and try updating through iTunes. Before you update through iTunes, make sure you update iTunes to the latest version (11.1) and that should work. If it does not work. I would take it into a Apple Store.