Hook Display and Output Cache

[eluser]slackero[/eluser]
Hello,

I am using $hook['display_override'] to implement global layout view which saves a lot of time. It's based on what I have found in this thread:
http://ellislab.com/forums/viewthread/57902/

In addition to just load the global layout I have put i18n substitution (to use simple @@My default text@@ replacer) in it too including custom replacer (defined in config) to be used for JavaScript, CSS and so on.

My main problem - how can I use CI output caching. If I enable output cache:

Code:

$this->output->cache(3600);

in my controller the cache file is written - but never used as expected (I guess).

Thanks
Oliver