I have Firefox 10.02. I have few years of experience with HTML, CSS, PHP and have never had such a problem before. I am changing CSS, for example, header height from 100px to 50px. Uploading style.css to my host. Refreshing page in firefox does not display changes. I close firefox open again - no changes. When I analyze element with firebug it shows that height still is 100px and not 50px. I restarting my PC and opening firefox and still no changes. I opening IETester and I can see changes, but not in firefox. In setting for clearing history I have "when closing firefox automatically clear all" and cache check box is marked. In Advance, network, I click Clear now and have cache 0 bytes in disk space. Nothing helps. Only next day I open firefox and see changes. What else I have to change to see changes right away? Please advise.
One possible answer: your ISP is using remote caching and simply doesn't check whether a file has changed. What do you see if you open your site from a completely different location, like a public terminal at the library?
To see changes right away, it is really better not to rely on your "live" site. Open the files locally from your hard drive, or install a pseudo-server like WAMP or MAMP. The second way is necessary if you use site-absolute links-- anything beginning in / slash-- because your browser alone can't deal with them.