HTML5: Offline Cache is ignored if loading different page under the same URL

I have a web application that has a constant URL and internal state machine. The states are changed via posts. I know it is a bad design and I should use the rest approach. But given this I have a following problem.

I use HTML5 offline cache (the manifest attribute in HTML tag). For the first page it is parsed and cached as I would expect (login page). But for the second page (main menu) the manifest included there is not parsed. No events are shown inside Chrome browser. If I change the URL a little by including a parameter then the manifest is parsed, but not before.

Event if I include everything in the login page manifest the second page downloads the same files again. Event if they are specified in the manifest for the first page.

Why this behaviour?

To answer it myself. It was looking so odd, simply because the cache is only parsed on GET calls and ignored on POST calls. Event if post loads another HTML page. To me this is a little bit silly but it seems that is how it works.

Now it finally works as it is supposed to.