I'm a noob in ruby and i'm trying to setup Ruby on Rails on ubuntu 12.04. I'm following steps as given in this site <https://www.digitalocean.com/community/articles/how-to-install-ruby-on-rails-on-ubuntu-12-04-lts-precise-pangolin-with-rvm>

But whenever i try to run this command > **rvm rubygems current** i get an error 

> 
> "Retrieving rubygems- There is no checksum for
>  '<http://production.cf.rubygems.org/rubygems/rubygems-.tgz>' or
>  'rubygems-.tgz', it's not possible to validate it. If you wish to
>  continue with unverified download add '--verify-downloads 1' after the
>  command."
> 
> 
> 

Any help on this on how to proceed.