got the problam in installation

hi, i installed ruby 1.8.6, installed gems 1.3.4.

when i am going install rails by using the following command,

gem install rails -v 2.0.2

it installs 2.3.2, i can't understand why this installs 2.3.2,
eventhough i mentioned the 2.0.2 version clearly.

can any one suggest me, how can i get rails 2.0.2 version........

I think you want
gem install rails -v=2.0.2