Do you have a firewall and are you blocking things with it? Privacy settings can influence the browser's download perfomance.
Do you allow Microsoft's automatic updates to Browsers and Windows? This could be why the refresh stopped working apparently spontaneously.
Could be a good idea to upgrade to IE6.
However, if you can afford the time on-line it could be no bad thing to let the Microsoft Auto-update have its evil way with you and fix any bugs. You always have the last say in what you are going to permit but you have to allow the time to sit, read and think about what is on offer because sometimes the jargon is tortuous.