reload from the Internet after about 12 hours, but that behaviour can be changed in the settings.

F5 is a command to ignore the cache and reload from outside, but how far outside it goes will depend on if the page is cached by the ISP of not, as they do NOT cache all the pages, just the most commonly used by their clients in the last few days or so.

If you want more people answering you have to ask the question over in Q&A.

This is more the discussions on the blogs, articles, or general stuff is at the Water Cooler - all requests for information should be in the Q&A.