Guys, I've been completely frustrated with this issue. But I **may** have found out why this issue is happening.
Problem?
Ever since I upgraded to iOS 7 my iPad 4th generation suddenly loses connection to my wifi (WPA/WPA2 protected) and gives me the "incorrect password" message. I am sure I am putting my password right.
If I leave my wifi unprotected (no password) it will connect easily.
What did I try?
I tried many stuff:
1 - taking off the apostrophe from my iPad's name - worked for a few days...
2 - resetting network settings
3 - rebooting router, iPad...
4 - removing the wifi password protection - iPad connects, but that's not an option for me
Roots of the problem?
Today my iPad lost connection and was giving me the "incorrect password" again.
Well my iPad is jailbroken, and I downloaded a program on Cydia that gives me informations about the wifis around me (WiFiFoFum).
And I found something odd...
On my router, the wifi is set for WPA/WPA2 protection.
On my computers, laptops etc. everything shows it is a WPA/WPA2 protected wifi.
But when I opened WiFiFoFum on my iPad and checked the info on my SSID, it was showing that my SSID had a WEP protection!
I went to the router and it was not WEP, but indeed was WPA/WPA2!
Only my iPad was showing it as being a WEP protected wifi.
So I set, on my router, my wifi to no protection and the iPad connected properly.
I then put the WPA/WPA2 protection again.
And when I re-opened the WiFiFoFum on the iPad, it was now showing that the wifi had the right protection: WPA!
And voila! Connected.
Fixing it?
So, I'm guessing the iOS 7 software messed it all up for some of us. So the iPad sometimes sees a WPA protection as a WEP protection, and thus gives us the information the password is wrong, even if we type it right.
I think we might be into something here. I don't know the actual solution besides trying to reboot your router, your iPad, and get your iPad to see it as a WPA, not WEP protection.
I don't think it is router related, as I have another iPad 2 and there it works perfectly fine (though on a friend's iPhone 5 he had the same problem as on my iPad 4th gen).
It might be some kinda of corruption on the data, when upgrading the firmware? Or some bug in the iOS 7 codes that makes it understand it wrong the protection type...
Maybe one of those days I will try and restore my iPad and monitor it, see if the iPad doensn't make confusions anymore.