Just to clarify, this problem is on your Windows system? To reload bypassing the cache, you can use Ctrl+Shift+r (instead of just Ctrl+r) or Shift+clicking the reload button in the address bar. To answer your question more directly, Firefox economizes on traffic by only checking whether a page has changed after it has expired (the server indicates the expiration when the page is sent). And yes, ''there is a setting for that.'' You can experiment with different values here: (1) In a new tab, type or paste '''about:config''' in the address bar and press Enter. Click the button promising to be careful. (2) In the search box above the list, type or paste '''cache''' and pause while the list is filtered (3) Double-click the '''browser.cache.check_doc_frequency''' preference and enter your preferred value (this is copied from a mozillaZine article): * '''0''' => Check for a new version of a page once per session (a session starts when the first application window opens and ends when the last application window closes). * '''1''' => '''Check for a new version every time a page is loaded.''' * '''2''' => Never check for a new version - always load the page from cache. * '''3''' => Check for a new version when the page is out of date. (Default) If you choose 1, does that solve the problem? Source: http://kb.mozillazine.org/Browser.cache.check_doc_frequency