它存在服务错误。这里是他们的回复：

Passenger和shell在两台不同的服务器上，i18n安装在
Passenger上，但是版本不是0.6.0。

所以我怀疑不同的宝石被用于乘客比使用的那些打包机

i get Passenger error on shared hosting

    Could not find i18n-0.6.0 in any of the sources (Bundler::GemNotFound)

but if i run "bundle install" it says everything is ok :(

and the contents of the Gemfile are:

source 'http://rubygems.org'
gem 'rake', '0.8.7'
gem 'tzinfo', '0.3.27'
gem 'mail', '2.2.16'
gem 'arel', '2.0.9'
gem 'rack', '1.2.2'
gem 'i18n', '0.6.0'

gem 'rails', '3.0.5'
gem 'mysql2'
gem 'paperclip'
gem 'devise'
gem 'jquery-rails'
gem 'acts-as-taggable-on'
gem "will_paginate", "~> 3.0.pre2"
gem 'tiny_mce'
gem "oa-oauth", :require => "omniauth/oauth"
gem "acts_as_list"

"bundle show i18n" gives

/usr/lib/ruby/gems/1.8/gems/i18n-0.6.0

is it the error in my app or error of the hosting? how do i solve it?

it was hosting service bug. here's their reply:

"Passenger and the shell are on two different servers. i18n was installed on Passenger, however the version was not 0.6.0."

so as i suspected different gems were used for passenger than the ones bundler used