caches_page issue - seems to be caching but not retrieving!

Hi all,
I'm currently trying to set up caching on my site and am starting by
trying to cache my homepage but am having a few problems as although it
seems to be caching (in the log I've got 'Cached page: /main.html
(0.00048)
'), when I reload, it performs all the queries again and doesn't appear
to be retrieving the file from the cache.

Just to give you a bit of background, I have a default route set up
which states the following:

map.home '', :controller => 'main', :action => "index"

The index action simply queries the database storing the outputs in a
hash which is used within the view. I have the following queries within
the controller:

def index
    @hostels=Hostel.count
    @cities=City.find(:all, :order => "number_of_hostels DESC", :limit
=> "75", :include => "country")
    @max_size=City.maximum('number_of_hostels')
    @review=Review.find(:first, :order => 'updated_at desc')
end

In environments/development.rb I have the following line:

config.action_controller.perform_caching = true

In my controller I have the following lines:

caches_page :index

I've been tearing my hair out over this as I can't see why it wouldn't
work - would very much appreciate it if someone can point me in the
right direction!

One other thing is that this appears to work if I change caches_page to
caches_action...
Thanks a lot,
Jonathan