That looks like it's doing a mandatory password change, the first prompt is to login, the next two is what you normally see when you run passwd (old password check, then new password to change to). Doen't look like a problem.
If they are getting this everytime then it's probably an issue with your password aging (have you checked that the settings are correct - not too short?)
If it's neither of these and no other users on the server are having issues, a lot of problems in NIS+ are due to sync problems Get them to leave it alone for one sync period without changing anything, then log in again.
If all else fails, delete their NIS creds and regenerate them.
While NIS (aka YP) is pretty solid, NIS+ is very buggy and unreliable on solaris, we've used it and will never do so again - piece of rubbish
I'd recommend going to an alternate product (eg LDAP, control-S)