Gem::RemoteFetcher::FetchErro when installing rails

I am trying to install rails on Ubuntu 8.10, and met following errors.
Please
help me get through.Thanks.

root@pierr-desktop:~# gem install rails
ERROR: While executing gem … (Gem::RemoteFetcher::FetchError)
bad response 500
(http://gems.rubyforge.vm.bytemark.co.uk/gems/actionpack-2.3.4.gem)

#other information
root@pierr-desktop:~# ruby -v
ruby 1.8.7 (2008-08-11 patchlevel 72) [i486-linux]
root@pierr-desktop:~# gem -v
1.2.0
root@pierr-desktop:~# gem list

*** LOCAL GEMS ***

activerecord (2.3.4)
activesupport (2.3.4, 1.4.4)
daemons (1.0.10)
gem_plugin (0.2.3)
rack (1.0.1)
rake (0.8.7, 0.8.3)
wirble (0.1.3)


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You may be hitting a busy site and timing out. You could try re-
ordering the sources listed in your .gemrc file or just add gemcutter
(http://gemcutter.org/) and give that a try.

I’m not sure what to suggest for best order. For reference, here’s
what my .gemrc looks like right now:

$ cat .gemrc

:backtrace: false
:benchmark: false
:bulk_threshold: 1000
:sources: