Rails rake throws error : no such file to load -- bundler/setup - ruby-on-rails-3

Question

When I run rake -T (or any rake command) I ran into this error:
$ rake -T
rake aborted!
no such file to load -- bundler/setup
<internal:lib/rubygems/custom_require>:29:in `require'
<internal:lib/rubygems/custom_require>:29:in `require'
/home/myself/rails/RailApp1/config/boot.rb:6:in `<top (required)>'
<internal:lib/rubygems/custom_require>:29:in `require'
<internal:lib/rubygems/custom_require>:29:in `require'
/home/myself/rails/RailApp1/config/application.rb:1:in `<top (required)>'
<internal:lib/rubygems/custom_require>:29:in `require'
<internal:lib/rubygems/custom_require>:29:in `require'
/home/myself/rails/RailApp1/Rakefile:5:in `<top (required)>'
/usr/lib/ruby/1.9.1/rake.rb:2373:in `load'
/usr/lib/ruby/1.9.1/rake.rb:2373:in `raw_load_rakefile'
/usr/lib/ruby/1.9.1/rake.rb:2007:in `block in load_rakefile'
/usr/lib/ruby/1.9.1/rake.rb:2058:in `standard_exception_handling'
/usr/lib/ruby/1.9.1/rake.rb:2006:in `load_rakefile'
/usr/lib/ruby/1.9.1/rake.rb:1991:in `run'
/usr/bin/rake:28:in `<main>'
I have checked the location of rake and bundler:
$ which rake
/usr/bin/rake
$ which bundle
/usr/bin/bundle
I also found these directory.
/usr/lib/ruby/gems/1.8/gems/bundler-1.0.14/lib/bundler/
/usr/lib/ruby/gems/1.8/gems/bundler-1.0.15/lib/bundler/
/usr/lib/ruby/gems/1.8/gems/rake-0.9.2/lib/rake/
When I run bundle exec rake *:
$bundle exec rake -T
Could not find rake-0.9.2 in any of the sources
Run 'bundle install' to install missing gems
when I run bundle install in my application:
$bundle install
Using rake (0.9.2)
Using multi_json (1.0.3)
Using activesupport (3.1.1)
Using builder (3.0.0)
Using i18n (0.6.0)
Using activemodel (3.1.1)
Using erubis (2.7.0)
Using rack (1.3.4)
Using rack-cache (1.1)
Using rack-mount (0.8.3)
Using rack-test (0.6.1)
Using hike (1.2.1)
Using tilt (1.3.3)
Using sprockets (2.0.2)
Using actionpack (3.1.1)
Using mime-types (1.16)
Using polyglot (0.3.2)
Using treetop (1.4.10)
Using mail (2.3.0)
Using actionmailer (3.1.1)
Using arel (2.2.1)
Using tzinfo (0.3.30)
Using activerecord (3.1.1)
Using activeresource (3.1.1)
Using bundler (1.0.21)
Using coffee-script-source (1.1.2)
Using execjs (1.2.9)
Using coffee-script (2.2.0)
Using rack-ssl (1.3.2)
Using json (1.6.1)
Using rdoc (3.10)
Using thor (0.14.6)
Using railties (3.1.1)
Using coffee-rails (3.1.1)
Using jquery-rails (1.0.14)
Using rails (3.1.1)
Using sass (3.1.10)
Using sass-rails (3.1.4)
Using sqlite3 (1.3.4)
Using uglifier (1.0.3)
But the error remains, very confused about this..