Browsers are notorious at hanging on tenaciously to cached pages. This problem is evident in Ajax applications when sending XMLHTTPRequest GET requests to Internet Explorer. Even when you use all manner of fancy headers like "Pragma: no-cache" or "Cache-Control: must-revalidate" you'll often find that you receive a cached page rather than a 'live' one. Here's something else you can try, which has worked well for me, and essentially only needs one line of Javascript.