Unix authentication ?

I was always under the impression that you don't need a password on Unix, to make a remote call to Informix (tcp connection), as long as your username exists in the operating system. I have a database server, and 4 application servers, and my users do not have a password on the database server, so they can't physically log in there, however they still connect to Informix on the database server. BUT, one of our Java applications does the same thing, and for some reason it needs a home directory as well as a password on Unix. If I leave the username/password, but give it a fake home directory, Java gives me an error, and cannot connect to Informix - why is this ? I am using IDS 7.31FD3, and Solaris 9 Dirk Moolman Database and Unix Administrator MXGROUP "People demand freedom of speech as a compensation for the freedom of thought which they seldom use." >>> sending to informix-list