The web browser I am currently using is FireFox and it has been my main browser for at least four years. I have no problem accessing the forum. I understand the problem your having, basically it loads the requested page in parts.
If you were to time how long it took to load in IE vs FireFox you would find that Firefox's the duration is likely to be the same, if not faster. This is the way FireFox renders pages, it likes to render them in parts. I have experienced the problem you are having. It starts off blank, and then loads the page in parts. All browsers interprete pages differently.
It also depends on your Internet connection, to how fast the parts show render. As I said in a previous thread, I have a 1.5mb/s connection so I don't have a problem regarding speed. However at times Cyprus-Forum is slower that other sites, particularly as all it's content is pulled out of some type of database.
As for the cache, I don't this it has anything to do with it, you can do as Antreis stated just to see the results. My personally feel it's your Internet connection not the browser. IE loads the page at once but the loading time is always the same, if not slower in IE.
Hope this help, by the way "Rediscover the Web".