I hadn't tried update-alternatives yet, but there was no java installed at the moment that I (re)installed sun-java5; so I expected the java executable and stuff somewhere else.
The default way I do java development is with manually downloaded installers from java.sun.com, installing them either in /usr/local/ or in my homedirectory.
I guess I should be "complaining" in the ubuntu thread or in the ubuntu forums and not here
Thanks for the update-alternatives hint, I can always try to use that next time.