Topic: problems with oracle server

//sorry for bad english because it is not my native language
i'm working on ubuntu 11.04; i need to create some rails application with oracle database on local computer.
i installed:  ruby 1.9.2, rails 3.1, oracle 10g XE, rubu-oci8 2.0.6, gem 'activerecord-oracle_enhanced-adapter', create database user named 'orak' with password 'orakpass' through 127.0.0.1:8080/apex, i maked new application 'orak' with database.yml parameters

development:
  adapter: oracle_enhanced
  database: 127.0.0.1/orak
  username: orak
  password: oraclepass

test:
  adapter: oracle_enhanced
  database: 127.0.0.1/orak
  username: orak
  password: oraclepass

production:
  adapter: oracle_enhanced
  database: 127.0.0.1/orak
  username: orak
  password: oraclepass

next i'm doing simple scaffold, and trying to rake db:create
result:
rake db:create
Please provide the SYSTEM password for your oracle installation
>oraclepass
rake aborted!
ORA-12514: TNS:listener does not currently know of service requested in connect descriptor

Tasks: TOP => db:create
(See full trace by running task with --trace)

but I can connect with  sqlplus orak/oraclepass@127.0.0.1
i had not work with oracle before, i had search with the google hard and not found answer. 
what i'm doing wrong?

Re: problems with oracle server

I have the same message as you have.
Did you manage to have it working ?
Thanks.