`add_frozen_gem_path': undefined method `source_index' for Gem:Module (NoMethodError) i am getting this error when i try running my server

`add_frozen_gem_path': undefined method `source_index' for Gem:Module
(NoMethodError) i am getting this error when i try running my server

from
/home/rakesh/.rvm/gems/ruby-1.8.7-p374/gems/rails-2.3.5/lib/initializer.rb:298:in
`add_gem_load_paths'
from
/home/rakesh/.rvm/gems/ruby-1.8.7-p374/gems/rails-2.3.5/lib/initializer.rb:132:in
`process'
from
/home/rakesh/.rvm/gems/ruby-1.8.7-p374/gems/rails-2.3.5/lib/initializer.rb:113:in
`send'
from
/home/rakesh/.rvm/gems/ruby-1.8.7-p374/gems/rails-2.3.5/lib/initializer.rb:113:in
`run'
from /home/rakesh/rails/rankfedena/config/environment.rb:6
from
/home/rakesh/.rvm/rubies/ruby-1.8.7-p374/lib/ruby/site_ruby/1.8/rubygems/core_ext/kernel_require.rb:112:in
`gem_original_require'
from
/home/rakesh/.rvm/rubies/ruby-1.8.7-p374/lib/ruby/site_ruby/1.8/rubygems/core_ext/kernel_require.rb:112:in
`require'
from
/home/rakesh/.rvm/gems/ruby-1.8.7-p374/gems/activesupport-2.3.5/lib/active_support/dependencies.rb:156:in
`require'
from
/home/rakesh/.rvm/gems/ruby-1.8.7-p374/gems/activesupport-2.3.5/lib/active_support/dependencies.rb:521:in
`new_constants_in'
from
/home/rakesh/.rvm/gems/ruby-1.8.7-p374/gems/activesupport-2.3.5/lib/active_support/dependencies.rb:156:in
`require'
from
/home/rakesh/.rvm/gems/ruby-1.8.7-p374/gems/rails-2.3.5/lib/commands/server.rb:84
from
/home/rakesh/.rvm/rubies/ruby-1.8.7-p374/lib/ruby/site_ruby/1.8/rubygems/core_ext/kernel_require.rb:64:in
`gem_original_require'
from
/home/rakesh/.rvm/rubies/ruby-1.8.7-p374/lib/ruby/site_ruby/1.8/rubygems/core_ext/kernel_require.rb:64:in
`require'
from ./script/server:3