cannot connect in jruby rails for newbie using jruby-1.5.0 final and rails 2.3.3

can't connect nor db:migrate using jruby-1.5.0(final) and rails 2.3.3
on a windows XP machine
here is my database.yml:
development:
    adapter: jdbc
    driver: oracle.jdbc.driver.OracleDriver
    url: jdbc:oracle:thin:@localhost:1521:monkey
    username: scott
    password: tiger1

C:\comics-catalog>jruby -S rake db:migrate --trace --verbose
(in C:/comics-catalog)
** Invoke db:migrate (first_time)
** Invoke environment (first_time)
** Execute environment
** Execute db:migrate
rake aborted!
The driver encountered an error:
org.jruby.runtime.builtin.IRubyObject.setInstan
ceVariable(Ljava/lang/String;Lorg/jruby/runtime/builtin/
IRubyObject;)Lorg/jruby/
runtime/builtin/IRubyObject;
c:/jruby-1.5.0/lib/ruby/gems/1.8/gems/ActiveRecord-JDBC-0.5/lib/
active_record/co
nnection_adapters/jdbc_adapter.rb:265:in `initialize'