Thread:Project:Support desk/Extension ArticlePageDataBefore/reply

That's because, not every time you request a page, it will be parsed :) Parsing takes much recources, so a page normally will be parsed one time and will be cached. If the content doesn't change (or you don't do a fake edit), the users will get the cached version of the page, which is ok, because the content haven't changed :)

As an idea, you could try to change the content of a page (Internal/Employees) with your Extension and include this page into the page where you use the the hook atm (.