IE slow to load then shuts down

Hi I am having this problem on one of my home computers (winXP)and have seen and heard of it on other machines (winME and XP) and various versions of IE from 4.0 to 6.0. the initial loading of takes 30 to 60 seconds at which time there is nothing you can do (I used to be able to change addresses and go to alternate sights as soon as IE address bar was available. Also when surfing some sights IE will completely shut down closing all IE windows Does not occur in all sight. My virus definitions are up to date. compleete scan done often, firewall detects nothing.