gem fetching error

I am trying to install some application using gem, but I keep on getting
the error. I tried with 'gem clean' and 'gem update'. The latter gives
the following error (the same error is replicable when I try any ruby
applications):

# gem update --debug
Exception `Errno::ENOENT' at
/usr/lib/ruby/site_ruby/1.8/rubygems/config_file.rb:51 - No such file or
directory - /root/.gemrc
Exception `NameError' at
/usr/lib/ruby/site_ruby/1.8/rubygems/command_manager.rb:145 -
uninitialized constant Gem::Commands::BuildCommand
Exception `NameError' at
/usr/lib/ruby/site_ruby/1.8/rubygems/command_manager.rb:145 -
uninitialized constant Gem::Commands::CertCommand
Exception `NameError' at
/usr/lib/ruby/site_ruby/1.8/rubygems/command_manager.rb:145 -
uninitialized constant Gem::Commands::CheckCommand
Exception `NameError' at
/usr/lib/ruby/site_ruby/1.8/rubygems/command_manager.rb:145 -
uninitialized constant Gem::Commands::ContentsCommand
Exception `NameError' at
/usr/lib/ruby/site_ruby/1.8/rubygems/command_manager.rb:145 -
uninitialized constant Gem::Commands::DependencyCommand
Exception `NameError' at
/usr/lib/ruby/site_ruby/1.8/rubygems/command_manager.rb:145 -
uninitialized constant Gem::Commands::EnvironmentCommand
Exception `NameError' at
/usr/lib/ruby/site_ruby/1.8/rubygems/command_manager.rb:145 -
uninitialized constant Gem::Commands::HelpCommand
Exception `NameError' at
/usr/lib/ruby/site_ruby/1.8/rubygems/command_manager.rb:145 -
uninitialized constant Gem::Commands::InstallCommand
Exception `NameError' at
/usr/lib/ruby/site_ruby/1.8/rubygems/command_manager.rb:145 -
uninitialized constant Gem::Commands::OutdatedCommand
Exception `NameError' at
/usr/lib/ruby/site_ruby/1.8/rubygems/command_manager.rb:145 -
uninitialized constant Gem::Commands::PristineCommand
Exception `NameError' at
/usr/lib/ruby/site_ruby/1.8/rubygems/command_manager.rb:145 -
uninitialized constant Gem::Commands::QueryCommand
Exception `NameError' at
/usr/lib/ruby/site_ruby/1.8/rubygems/command_manager.rb:145 -
uninitialized constant Gem::Commands::ListCommand
Exception `NameError' at
/usr/lib/ruby/site_ruby/1.8/rubygems/command_manager.rb:145 -
uninitialized constant Gem::Commands::RdocCommand
Exception `NameError' at
/usr/lib/ruby/site_ruby/1.8/rubygems/command_manager.rb:145 -
uninitialized constant Gem::Commands::SearchCommand
Exception `NameError' at
/usr/lib/ruby/site_ruby/1.8/rubygems/command_manager.rb:145 -
uninitialized constant Gem::Commands::SourcesCommand
Exception `NameError' at
/usr/lib/ruby/site_ruby/1.8/rubygems/command_manager.rb:145 -
uninitialized constant Gem::Commands::SpecificationCommand
Exception `NameError' at
/usr/lib/ruby/site_ruby/1.8/rubygems/command_manager.rb:145 -
uninitialized constant Gem::Commands::UninstallCommand
Exception `NameError' at
/usr/lib/ruby/site_ruby/1.8/rubygems/command_manager.rb:145 -
uninitialized constant Gem::Commands::UnpackCommand
Exception `NameError' at
/usr/lib/ruby/site_ruby/1.8/rubygems/command_manager.rb:145 -
uninitialized constant Gem::Commands::CleanupCommand
Exception `NameError' at
/usr/lib/ruby/site_ruby/1.8/rubygems/command_manager.rb:145 -
uninitialized constant Gem::Commands::UpdateCommand
Updating installed gems...
Exception `ArgumentError' at
/usr/lib/ruby/site_ruby/1.8/rubygems/source_info_cache.rb:68 - marshal
data too short
Exception `ArgumentError' at
/usr/lib/ruby/site_ruby/1.8/rubygems/source_info_cache.rb:68 - marshal
data too short
Exception `URI::InvalidURIError' at /usr/lib/ruby/1.8/uri/common.rb:436
- bad URI(is not URI?): ://:
Exception `URI::InvalidURIError' at
/usr/lib/ruby/site_ruby/1.8/rubygems/remote_fetcher.rb:60 - bad URI(is
not URI?): ://:
Exception `Gem::OperationNotSupportedError' at
/usr/lib/ruby/site_ruby/1.8/rubygems/source_index.rb:305 - No quick
index found: bad URI(is not URI?): ://:
Bulk updating Gem source index for: http://gems.rubyforge.org
Exception `URI::InvalidURIError' at /usr/lib/ruby/1.8/uri/common.rb:436
- bad URI(is not URI?): ://:
Exception `URI::InvalidURIError' at /usr/lib/ruby/1.8/uri/common.rb:436
- bad URI(is not URI?): ://:
Exception `URI::InvalidURIError' at
/usr/lib/ruby/site_ruby/1.8/rubygems/remote_fetcher.rb:60 - bad URI(is
not URI?): ://:
Exception `URI::InvalidURIError' at /usr/lib/ruby/1.8/uri/common.rb:436
- bad URI(is not URI?): ://:
Exception `URI::InvalidURIError' at
/usr/lib/ruby/site_ruby/1.8/rubygems/remote_fetcher.rb:60 - bad URI(is
not URI?): ://:
Exception `Gem::RemoteSourceException' at
/usr/lib/ruby/site_ruby/1.8/rubygems/source_index.rb:292 - Error
fetching remote gem cache: bad URI(is not URI?): ://:
ERROR: While executing gem ... (Gem::RemoteSourceException)
    Error fetching remote gem cache: bad URI(is not URI?): ://:

New to ruby, any pointer?

I have same problem- Gem sucks. Wonderful that no one has replied to
you yet.