Well I'm at my wits end...

I have an oracle database on an HPUX box that I can connect to using
this code:

require 'oci8'

connection = OCI8.new('user','passwd','connectstring')
connection.exec("select table_row from table") do |row|
puts 'column 1: ' + row[0] # outputs "dummy: X"
end

Works beautifully, but when I set up a rails application I get

 OCIError in ArtifactController#new

ORA-12154: TNS:could not resolve the connect identifier specified

Here is my database.yml file
===================================================

# MySQL (default setup).  Versions 4.1 and 5.0 are recommended.
#
# Install the MySQL driver:
#   gem install mysql
# On MacOS X:
#   gem install mysql -- --include=/usr/local/lib
# On Windows:
#   There is no gem for Windows.  Install mysql.so from RubyForApache.
#   http://rubyforge.org/projects/rubyforapache
#
# And be sure to use new-style password hashing:
#   http://dev.mysql.com/doc/refman/5.0/en/old-client.html
development:
  adapter: oci
  username: xxxxxxxxx
  password: xxxxx
  host: host_alias:port

# Warning: The database defined as 'test' will be erased and
# re-generated from your development database when you run 'rake'.
# Do not set this db to the same as development or production.
test:
  adapter: oci
  username: xxxxxxxxx
  password: xxxxx
  host: host_alias:port

production:
  adapter: oci
  username: xxxxxxxxx
  password: xxxxx
  host: host_alias:port

I can't think of anything to check and google doesn't tell me much
except  for

http://ruby.about.com/od/enterprise/ss/ruby_oracle_7.htm

Which is where I started out 3 hrs ago.