pljava I/O Error

Hi

I am not sure if this is the right group, but I did not found a better
fitting one. So I hope you can help me. I have Ubuntu with Postgresql
8.2 running. I try to install pljava and have completed the Steps from
http://wiki.tada.se/display/pljava/Posix+Installation sucessfully. But
I have trouble on installing the example.jar ( http://wiki.tada.se/display/pljava/Sample+Tests
)

Welcome to psql 8.2.6, the PostgreSQL interactive terminal.

Type: \copyright for distribution terms
\h for help with SQL commands
\? for help with psql commands
\g or terminate with semicolon to execute query
\q to quit

postgres=# SELECT sqlj.install_jar('/usr/lib/postgresql/8.2/pljava/
examples.jar', 'samples', true);
ERROR: java.sql.SQLException: I/O exception reading jar file: no
protocol: /usr/lib/postgresql/8.2/pljava/examples.jar

But the file is there:
cikic(at)MrZylinder:~$ ll /usr/lib/postgresql/8.2/pljava/examples.jar
-rw-rw-rw- 1 postgres cikic 42246 2008-02-04 10:32 /usr/lib/postgresql/
8.2/pljava/examples.jar

My postgres.conf ends with:
#---------------------------------------------------------------------------
# CUSTOMIZED OPTIONS
#---------------------------------------------------------------------------

#custom_variable_classes = '' # list of custom variable
class names

#pljava
dynamic_library_path ='$libdir:/usr/lib/postgresql/8.2/pljava'
pljava.classpath='/usr/lib/postgresql/8.2/pljava/pljava.jar'
custom_variable_classes = 'pljava'

What is the missing thing?

Thank you for help
Christian