Can't Get Caching to Work with Heroku and Memcache

I’m on Heroku and trying to implement caching in my Rails app, but I’m running into some problems that I don’t understand. I thought it would be easy after reading the Rails Guide and Heroku docs on caching strategies, but apparently doing something wrong.

Issue 1: view of action doesn’t seem to expire Issue 2: when I use :layout => false, both my admin and app layout are used (trying to only get the application layout)

Any help for this newbie would be most appreciated!

production.rb (also installed dalli per heroku documentation)

config.cache_store = :dalli_store
config.action_controller.perform_caching = true (added after reading http://bit.ly/oRKub1)

controller

layout 'admin'
caches_action :show, :layout => false

def show
  render :layout => 'application'
end

def update
  expire_action :action => :show
end

I tried to test the expiration by changing a product, but the show view does not expire. So when I look at edit view for products, which I’m not caching, I can see the change saved (just added a word to the title), but when I view show, it still has the old info.