When you are developing a site, there is a heck of a lot of “refreshing” going on. You start to get a pretty good feel for what your browser is going to pick up on a single refresh, and what it won’t. For example, I find that if I over-write an image file on the server, it will take me two refreshes for that image to update on the live site. Then maybe I’ll pop over into Opera and see how the site is doing over there, only to find on the first render of the page that is a really old version. Uh oh. Refresh. Refresh. Oh… there it is.