Sorry to just dump the error in the title - but this is driving me nuts! I'm having to move clients from one server to another, as rails apps just refuse to start on this one machine. Upon starting the app I get a pile of this repeated dozens of times (even with a completely empty app I still get a few lines of this): NOTE: Gem::SourceIndex#add_spec is deprecated, use Specification.add_spec. It will be removed on or after 2011-11-01. Gem::SourceIndex#add_spec called from /usr/lib/ruby/site_ruby/1.8/rubygems/source_index.rb:127. I have matched all of the gems I understand the app uses with the working server, moved /usr/bin/gem and reinstalled gem using the cpanel /scripts/installruby - but it boosted it up to v1.8.8 whereas the working server is only running 1.3.7 and I'm loath to touch that server in case an update breaks it! Any clues as to what this error is indicating, and how to fix this?