Java Technology Forums - target 1.1 nevermore ?:

With the 1.5 compiler the *default* source version is 1.5. So if you only specify 'target 1.1' then you are effectively saying 'source 1.5 target 1.1' But one cannot generate code for a 1.1 jvm from 1.5 source.

Therefore, in order to get this to work with the 1.5 compiler, you need to explicitly set the source code version by saying:
javac -source 1.3 -target 1.1

Hopefully this means I'll be able to target my StarMax with jive I compile on my iBook with OS X. We'll see.