Topic: dispatch fails with Socket operation on non-socket (Errno::ENOTSOCK)

Hi,
I am trying to run an application (Redmine 2.1-stable) on Hostmonster, but the dispatch fails with the error below, search engines do not give much advice on this. This does not look like a Redmine issue, but more like an environment/configuration problem, so I am asking for some advice here.

/home/user/ruby/gems/gems/fcgi-0.8.8/lib/fcgi.rb:113:in `accept': Socket operation on non-socket (Errno::ENOTSOCK)
  from /home/user/ruby/gems/gems/fcgi-0.8.8/lib/fcgi.rb:113:in `session'
  from /home/user/ruby/gems/gems/fcgi-0.8.8/lib/fcgi.rb:104:in `each_request'
  from /home/user/ruby/gems/gems/fcgi-0.8.8/lib/fcgi.rb:36:in `each'
  from /home/user/ruby/gems/gems/rack-1.4.1/lib/rack/handler/fastcgi.rb:27:in `run'
  from public/dispatch.fcgi:24

At the moment I am already running Redmine 1.4.4 successfully and it uses fcgi-0.8.8, as well. So it does not really make sense to me, why the same script fails to execute.

gem env

RubyGems Environment:
  - RUBYGEMS VERSION: 1.7.2
  - RUBY VERSION: 1.8.7 (2012-02-08 patchlevel 358) [x86_64-linux]
  - INSTALLATION DIRECTORY: /home/user/ruby/gems
  - RUBY EXECUTABLE: /usr/bin/ruby
  - EXECUTABLE DIRECTORY: /home/user/ruby/gems/bin
  - RUBYGEMS PLATFORMS:
    - ruby
    - x86_64-linux
  - GEM PATHS:
     - /home/user/ruby/gems
  - GEM CONFIGURATION:
     - :update_sources => true
     - :verbose => true
     - :benchmark => false
     - :backtrace => false
     - :bulk_threshold => 1000
     - "gem" => "--remote --no-rdoc --no-ri --run-tests"
     - "gempath" => ["/home/user/ruby/gems"]
     - "rdoc" => "--inline-source --line-numbers"
     - "gemhome" => "/home/user/ruby/gems"
  - REMOTE SOURCES:
     - http://rubygems.org/

Any help, directions or advice highly appreciated.
Thanks!