Problem using rails 2.1.0 and gettext

Hi all,
  i'm traing to localize in italian my rails app using gettext. All
goes ok until i implement validations. Using for example
validates_presence_of to validate an associations, on errors the
application blow up and i receive an error message of this kind:

/usr/lib/ruby/gems/1.8/gems/gettext-1.92.0/lib/gettext/
active_record.rb:285:in `=~'
/usr/lib/ruby/gems/1.8/gems/gettext-1.92.0/lib/gettext/
active_record.rb:285:in `localize_error_message'
/usr/lib/ruby/gems/1.8/gems/gettext-1.92.0/lib/gettext/
active_record.rb:284:in `each'
/usr/lib/ruby/gems/1.8/gems/gettext-1.92.0/lib/gettext/
active_record.rb:284:in `localize_error_message'
/usr/lib/ruby/gems/1.8/gems/gettext-1.92.0/lib/gettext/
active_record.rb:317:in `localize_error_messages'
/usr/lib/ruby/gems/1.8/gems/activerecord-2.1.0/lib/active_record/
validations.rb:139:in `each'
/usr/lib/ruby/gems/1.8/gems/activerecord-2.1.0/lib/active_record/
validations.rb:139:in `each'
/usr/lib/ruby/gems/1.8/gems/activerecord-2.1.0/lib/active_record/
validations.rb:139:in `each_key'
/usr/lib/ruby/gems/1.8/gems/activerecord-2.1.0/lib/active_record/
validations.rb:139:in `each'
/usr/lib/ruby/gems/1.8/gems/gettext-1.92.0/lib/gettext/
active_record.rb:314:in `localize_error_messages'
/usr/lib/ruby/gems/1.8/gems/gettext-1.92.0/lib/gettext/
active_record.rb:332:in `on'
/usr/lib/ruby/gems/1.8/gems/actionpack-2.1.0/lib/action_view/helpers/
active_record_helper.rb:230:in `content_tag'
/usr/lib/ruby/gems/1.8/gems/actionpack-2.1.0/lib/action_view/helpers/
form_tag_helper.rb:132:in `label_tag'
/usr/lib/ruby/gems/1.8/gems/actionpack-2.1.0/lib/action_view/helpers/
form_helper.rb:524:in `to_label_tag'
/usr/lib/ruby/gems/1.8/gems/actionpack-2.1.0/lib/action_view/helpers/
form_helper.rb:336:in `label'
/usr/lib/ruby/gems/1.8/gems/gettext-1.92.0/lib/gettext/rails.rb:310:in
`label'

It seems there is some problems in gettext, but i don' konw how to fix
it, any suggestion?

thanks,
   nelson