Preload all posts

Hi,
I am having a problem with preloading all posts. I have also turned on the preload of categories and tags, but it preloads only about 80 pages. And it sends me regularly emails that: Preload may have stalled – Preload has been restarted.

When I do it manually and I click on every category and tag and post, than it will preload about 300 pages but after some time it goes down again, even though I have garbage collection turn off and there is preload mode turn on. Is there a way to preload all the posts, pages and categories and refresh the cache only when I do a change there? And should it be working like this?

Thanks for any help