That computer should load anything you throw at it in no time at all. I suspect your 56k connection may not be able to keep up with all the web page content. Your connection speed could vary at any given time as well. Seems to me I had that trouble years ago when I switched my phone to cable. Dumped the 56k modem and went with cable internet. Don't know if I could trouble shoot that now its been so long since I used a 56k modem. You could try the Firefox browser instead of Internet Explorer. It's a little liter and may load faster:
http://www.mozilla.com/en-US/firefox/
It's all I use now. If you are daring try looking at your modem settings???
