.pgpass being ignored

I am trying to write a script that will create and populate a
database.  I don't want to enter a password every time so I want to
use a .pgpass file.  It has the correct permissions:

    $ ls -l $PGPASSFILE
    -rw-------  1 Stephen  staff  43 21 Jun 14:48 /Users/Stephen/.pgpass

However, when I call createdb, it fails:

    $ createdb -h 192.168.1.4 -U postgres --no-password JobSearch
    createdb: could not connect to database postgres: fe_sendauth: no
password supplied

This is the contents of my .pgpass file:

    192.168.1.4:5432:DatabaseName:postgres:thisIsTheCorrectPassword

If I omit the --no-password option it will prompt me for a password
and the command will succeed.  I am using 9.0.10 from MacPorts.

What am I doing wrong?

...Stephen