title: couldn't install gems - Gem not found Exception
body: <p>os: os x lion</p>
  
  <p>i was not able to install any gems . checked the gem sources <a href="http://rubygems.org" rel="nofollow">http://rubygems.org</a> was in the list. tried using the system gem (ruby 1.8.7) and rvm ruby (1.9.2). For any gem install GemNotFoundException was thrown. </p>
  
  <pre><code>gem install sinatra --no-ri --no-rdoc
  ERROR:  Could not find a valid gem 'sinatra' (&gt;= 0) in any repository
  ERROR:  Possible alternatives: sinatra
  SKYLINE:rubygems-1.8.6 avinash$ gem sources
  *** CURRENT SOURCES ***
  
  http://rubygems.org/
  </code></pre>
  
  <p>Any ideas?</p>
  
  <p>Help would be appreciated.</p>
  
  <p>-Avinash</p>