I have the same problem. I can log in at the spotify webpage on my iPhone via safari, but I can not log in via the app. I've recently changed my password 2 times. The app tells me always that I can't log in, username or password is wrong ... I'm sure it's the right password. Maybe it has something to do with the fact that I've cleared the spotify app today without logging out. Then I've installed it again and couldn't log in as mentioned above. Please help me.