Error : GettextTask constant Uninitalized

I am making my rails app i18n , so I used the
http://article.gmane.org/gmane.comp.lang.ruby.rails/16703/match=+easy+stepstutorial
and
Adminpanel , to configure my
environment.rb and rakefile, which are
http://rafb.net/paste/results/28mAay13.html and
http://rafb.net/paste/results/ev1bKI17.html respectively ,

can you help me on how to get this work

Thanks
Sekhar