login - Unable to mount home-directory for user after fresh install 14.04

I performed an fresh install of Ubuntu 14.04. I have /home on a different partition from root. Installing 14.04 and mounting /home went without any problem. During installation I was asked to make a user and I made a new user with my user-name and password. My home folder was correctly added to my user-name. After this I made users for my different family members and adding their existing home folder which went fine except for one.
In one case I could make the new user, same user-name as the home folder. Login for this user failed. The screen turns black and one would expect the desktop for this user to appear. I can hear the drum-sound which indicates that you are logged in, but the login-screen returns. I am unable to login for this one user.
If I try to login this user in cli everything is fine. I can browse the home folder and files.
Of course I don't want to loose the home folder for this user. What should I do?
Thanks in advance.