Would be v. grateful for any suggestions. For some weeks now I've been unable to load ds's school website or get on the National Lottery site. They start loading but never actually get anywhere. Am also having this problem with some other sites but not ones I'm that bothered about or use regularly - just when I'm following links. Can use MN, obv, and everything else...
Am on an elderly-ish Mac laptop (OSX) running Firefox (and have tried doing it in Safari just in case but that doesn't work either).
Are you fully up to date? It may be that thee web sites use some technology that your setup doesn't support any more. Do you run Software Update to keep Mac OS X up to date? And do you have the latest version of Firefox, which is 3.5? That may be it.
Well, if you can be bothered it's worth creating another user account on the Mac (go to System Preferences and to Accounts which is at the bottom left) and switching to that user, then seeing if the problem is the same. This will tell you if the problem is in your user cache or something to do with the operating system. You can delete the other user afterwards, although it won't take up much space.
Also switch your internet router off for at least 20 minutes, if you haven't recently, in case it's got its knickers in a twist.