My son has the original iPad (but with the latest iOS). He can use the YouTube application just fine, but when he tries to log in (say he wants to subscribe), it always rejects his user id and password. (email@example.com, xxxxx). He can enter it through Safari on the YouTube site and from a laptop on the You Tube site without problem. I've cleared the browser cache, but couldn't find any settings for YouTube. Does anyone know how to get it to accept his user ID/Password? I just says "authentication failed."