Cache expires too soon?

[eluser]krif[/eluser]
I have a quite strange problem here. In my controller, I have enabled output caching, set to 8 hours (480 minutes). When I visit the actual page, rendering time on the first call with emtpy cache is about 0.0184 s, on a subsequent call only about 0.0064 s.

Now when I come back later to my website, well under the 8 hours, on my initial load of the page, I again get a value of like with the empty cache and on a reload the page loads very fast again.

I know this is quite unspecific so far but it seems like the cache is expiring too soon.

Did anyone experience something similar? Might my hosting provider do some caching on the database queries that I don't know of?

[eluser]Neophyte[/eluser]
This is just a guess but is your server running an opcode cache (APC, XCache, Zend) If so it seems more likely that when you go back to the page later (but less than 8 hours) the page cache still exists and is served but the opcode cache of the PHP files will likely have expired or been pushed out of memory and it is this which is bumping up that initial page load when you go back to the page.