rails 3.0.0.beta3 error

Hello I am trying to install rails 3.0.0.beta3, when I run "gem install rails --pre" I get the following output:

Successfully installed rails-3.0.0.beta3
1 gem installed
Installing ri documentation for rails-3.0.0.beta3...
ERROR:  While executing gem ... (Errno::ENOENT)
No such file or directory - lib


When I run "rails -v" I get the following output

/Users/eniolopes/.rvm/rubies/ruby-1.8.7-p248/lib/ruby/site_ruby/1.8/rubygems.rb:777:in `report_activate_error': Could not find RubyGem rails (>= 0) (Gem::LoadError)
from /Users/eniolopes/.rvm/rubies/ruby-1.8.7-p248/lib/ruby/site_ruby/1.8/rubygems.rb:211:in `activate'
from /Users/eniolopes/.rvm/rubies/ruby-1.8.7-p248/lib/ruby/site_ruby/1.8/rubygems.rb:1056:in `gem'
from /Users/eniolopes/.rvm/rubies/ruby-1.8.7-p248/bin/rails:18


Here is my "gem list"
actionmailer (2.3.5)
actionpack (2.3.5)
activemodel (3.0.0.beta3, 3.0.0.beta2, 3.0.0.beta)
activerecord (2.3.5)
activeresource (2.3.5)
activesupport (3.0.0.beta3, 3.0.0.beta2, 3.0.0.beta)
authlogic (2.1.3)
builder (2.1.2)
bundler (0.9.5)
crack (0.1.7, 0.1.6)
cucumber (0.6.4, 0.6.2)
diff-lcs (1.1.2)
ffi (0.6.3, 0.6.2)
gemcutter (0.5.0)
hashie (0.2.0, 0.1.8)
httparty (0.5.2)
i18n (0.3.6, 0.3.3)
json_pure (1.2.3, 1.2.0)
memcache-client (1.8.1, 1.7.8)
oauth (0.3.6)
polyglot (0.3.1, 0.3.0)
rake (0.8.7)
rspec (1.3.0)
ruby-hmac (0.4.0)
rubygems-update (1.3.6, 1.3.5)
rvm (0.1.24, 0.1.15)
sinatra (0.9.4)
sqlite3 (0.0.8)
term-ansicolor (1.0.4)
thor (0.13.2)
treetop (1.4.4)
twitter (0.8.4)
tzinfo (0.3.16)
xmpp4r (0.5)
xmpp4r-simple (0.8.8)