I am trying to use the iSeries Navigator interface to
compile (and eventually run) some java code (that I still
need to develop).
Ok, this is entirely my opinion ... but trying to use iSeries Navigator
to do Java development is just plain wrong.
Use WDSC (or get a copy of Eclipse) to do your java development ...
you'll find it's FAR FAR FAR easier.
Develop the code on your PC, test it, make sure it's working the way you
want ... then consider deploying the code to your System i.
Use the right tool for the job ... and iSeries Nav just isn't the right
Unless, of course, I'm not understanding what you are trying to do.