Downgrading gems

Uninstall current i18n-gem:

gem list -d i18n

> i18n (0.5.0) […] Installed at: /Library/Ruby/Gems/1.8

sudo gem uninstall —install-dir /Library/Ruby/Gems/1.8 i18n -v 0.5.0

Install 0.3.7:

gem install i18n -v=0.3.7