Ruby on rails 3 Whenever install problem

I tried to install whenever for ruby but this keeps on failing. I tried:

sudo gem install whenever

That properly installed but i can not use the whenever 开发者_StackOverflow社区command. I tried to run a "bundle install" but that changend nothing

Then i followed a railscast of whenever (railcast) but when i try to run "sudo rake gems:install" i get this

sudo rake gems:install(in /home/ruben/Monitoring) 
Could not find rake-0.8.7 in any of the sources

If i look at the gem list is see that rake is installed!

*** LOCAL GEMS ***
abstract (1.0.0)
actionmailer (3.0.4, 3.0.3, 3.0.0)
actionpack (3.0.4, 3.0.3, 3.0.0)
activemodel (3.0.4, 3.0.3, 3.0.0)
activerecord (3.0.4, 3.0.3, 3.0.0)
activeresource (3.0.4, 3.0.3, 3.0.0)
activesupport (3.0.4, 3.0.3, 3.0.0)
acts-as-taggable-on (2.0.6)
arel (2.0.8, 2.0.7, 1.0.1)
bcrypt-ruby (2.1.4)
builder (2.1.2)
bundler (1.0.10)
daemon_controller (0.2.6)
devise (1.1.rc2)
erubis (2.6.6)
fastthread (1.0.7)
file-tail (1.0.5)
i18n (0.5.0, 0.4.2)
jquery-rails (0.2.7)
jrails (0.6.0)
mail (2.2.15)
mime-types (1.16)
mocha (0.9.11)
mysql (2.8.1)
mysql2 (0.2.6)
net-ping (1.4.0)
nifty-generators (0.4.4)
paperclip (2.3.8)
passenger (3.0.2)
polyglot (0.3.1)
rack (1.2.1)
rack-mount (0.6.13)
rack-test (0.5.7)
rails (3.0.3, 3.0.0)
rails3-jquery-autocomplete (0.6.2, 0.6.1)
railties (3.0.4, 3.0.3, 3.0.0)
rake (0.8.7)
redcar (0.10)
rmagick (2.13.1)
ruby-net-ldap (0.0.4)
rubyzip (0.9.4)
spruz (0.2.5)
sqlite3 (1.3.3)
sqlite3-ruby (1.3.3)
thor (0.14.6)
tiny_mce (0.1.4)
treetop (1.4.9)
tzinfo (0.3.24)
warden (0.10.7)

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I someone has the same problem just install whenever without the sudo command.