Rails 2.3 problem...

When moving to Rails 2.3.0RC1 I get an error with concat!? I can't
figure it out. See the dump below:

ActionView::TemplateError (You have a nil object when you didn't expect
it!
You might have expected an instance of Array.
The error occurred while evaluating nil.<<) on line #158 of
app/views/places/show.html.erb:
158: <div class="dottedSeparator"></div>
159: <h3><%= "What do you think about '%s'?" / @place %></h3>
160: <% end -%>
161: <% form_for([@place, @review = Review.new]) do |f| %>

    actionpack (2.3.0) lib/action_view/helpers/text_helper.rb:32:in
`concat'
    actionpack (2.3.0) lib/action_view/helpers/form_helper.rb:252:in
`form_for'
    app/views/places/show.html.erb:158

Any help is greatly appreciated!

It seems to be something with form_for and blocks or something?! It does
NOT appear in Rails 2.2.2 however :S

The problem was Erubis.
This (faster erb renderer) doesn't work with Rails 2.2.2 and 2.3 yet.