Each time you access a page using your web browser, the browser caches (stores) it. In this way, the page (including any images on the page) do not have to be retrieved each time from the remote web site when you click the Back or Forward buttons. You should clear the cache at times to allow your browser to function more efficiently.
Ctrl + F5 works on most browsers. If that doesn't seem to bring about the change, then use the following instructions:
Internet Explorer 7
1. From the Tools menu, select Internet Options... .
2. Choose the General tab.
3. Under Browsing history, click Delete... .
4. Next to "Temporary Internet Files", click Delete files... .
5. Click Close, and then click OK to exit.
Firefox 3 for Windows
From the Tools menu, select Clear Private Data, and then check Cache. Click Clear Private Data Now.
That's the two major browsers that folks are using. If someone comes along and is using one of the newer browsers, feel free to add to this list.