We have an application where we're allowing users to sign in using their Yahoo account. I'm noticing a problem where sign in doesn't seem to be working for users with older accounts. They click 'Sign in' from our site, provide their Yahoo credentials and give permissions to our application, but when they are redirected back to our site they are not signed in. If we try with a more recent account this isn't a problem. This seems to be a problem with older accounts that people haven't used in a while.
Is this a known problem? Is there a way around this?