When using a simple f.date_select, i got a nice “wrong number of arguments (3 for 2)”, turns out the problem lies with gettext localize, which overwrites select_month, but seems to break in rails 2.1.

To fix monkeypatch it:

#vendor/plugins/gettext_localize/lib/gettext_localize_extend.rb @line 172
  def select_month(date, options = {},html_options={})

Now it should do your bidding again 🙂