I am not able to login in gnome session and java session in Sun solaris 9& 10

I am not able to login in gnome session and java session in Sun solaris 9& 10 respectively through xmanager as a nis user, I am able to login in common desktop , but gnome session its not allowing , when I have given login credentials, its coming back to login screen, what shoul I do to allow nis users to access gnome session.

Thanks & Regards
Durgaprasad