I had this problem a while ago, I put it down to my connection speed. Then I noticed that my modem was constantly sending data! Turns out I had the opaserv worm which was clogging my modem and stoping me from getting images.
Is your modem constantly transfering data? Or doing it when not requested or when you open applications that have nothing to do with the web? I suggest first a firewall if not already have one. Even if this is not the problem. Then you can see who or what is trying to get in and out of your computer and block it or let it through.
Just a thought.
Omnis mico antequam dominus Spookster!