I have been seeing this problem on couple of our NIS+ Solaris client machines. The user home directories are on our file server and using automount on the client side, users log in to their home directories from SUN NIS+ clients.The permissions and automount files (auto_master, auto_home) are setup correctly. The same users can log on to other NIS+ clients with identical auto_master & auto_home directories.
I had open a sun service request on this and after going through different trouble shooting procedure they suggested that I do a hard mount to home directories!!! What is then the use of NIS+...
I hope to get a fix to this problem from this site.