Error when upgrade Redmine from 1.3.1 to 2.0.2

I have installed Bitnami Redmine 2.0.2 (Linux 64bit) on a Ubuntu-Server(11.04).

Everything is fine until i execute: rake db:migrate RAILS_ENV="production"

I got following error:

Could not find gem 'factory_girl_rails (>= 0) ruby' in any of the gem sources listed in your Gemfile.
Run `bundle install` to install missing gems.

Ok. Now i tried to install the missing gems with "bundle install". Following error appears:

Fetching source index for http://rubygems.org/
/opt/redmine-2.0.2-0/ruby/lib/ruby/site_ruby/1.8/rubygems.rb:594:in `initialize': not in gzip format (Zlib::GzipFile::Error)
    from /opt/redmine-2.0.2-0/ruby/lib/ruby/site_ruby/1.8/rubygems.rb:594:in `new'
    from /opt/redmine-2.0.2-0/ruby/lib/ruby/site_ruby/1.8/rubygems.rb:594:in `gunzip'
...

What i do wrong?