ok so i had some time finally and tested the new updated version of jamvm and classpath.
the new jamvm is pretty poor. i dont know what the idea is with jamvm. one version supports -jar and the next does not. the new 1.4.3 does not support -jar option whereas 1.4.2 did.
classpath 0.9.1 adds a lot of features like rmi server and certutil tools, but nothing that is really useful for a zaurus unless you want to turn your zaurus into a server.
i still think jamvm 1.4.2 with classpath 0.20 is the best mix at the moment.
as for the new jamvm, you will need to provide the following options for it to work
here is an example to run jedit:
-Djava.library.path=/usr/java/classpath/lib -cp /usr/local/share/jedit/4.2/jedit.jar org.gjt.sp.jedit.jEdit
however, jedit does not work properly. xmlj is missing