To avoid misunderstandings of my tip:

the folders to be renamed in
/usr/lib/java are:
lib , jre, include and bin

you find the folders (by the same name), that include the new java version in the SUBFOLDER of :

/usr/ name of the folder that contains new version

in my case:
/usr/j2sdk1.4.1_01

i hope, my first message did not cause any trouble by being not that explicitly ahhhmm, unmistakable...
;-]]]

hn/berlin