This might be a tricky one to explain so please bear with me. Sometimes, when I click on a link or type an address, the page will fail to load for any number of reasons. However, when this happens, sometimes Firefox doesn't save the URL of the page I attempted to visit in its address bar. Instead, the address bar is either blank or shows "about:blank". This means that hitting the Refresh button does nothing (since Firefox thinks there is no URL to refresh!). Another symptom of this problem is if you open a link in a new tab (or window), then immediately attempt to bookmark the page while it is still loading. Say, for example, a page is taking a bit too long to load and you decide to bookmark it for later viewing. It turns out that what you're actually bookmarking is - again - the URL "about:blank". This is incredibly frustrating behaviour. My expectation as a user is that *the moment you click or type a URL, that URL should be concretely cemented into the address bar*, and even if the page fails to load, takes a long time, or other problems occur, the refresh button should always work, the bookmark function should always work, and the window or tab should *always* have a concrete "identity" of that URL you clicked or typed. Does this make sense?