Since the thread is so old I am posting a new one. I have had a problem with IE8 freezing on some websites. I tried turning off IE8 smart screen filter, which helped. I removed some malware which may or may not have helped. I disabled anti-phishing in NIS and that really helped, but I still had the problem occasionally . Finally I disabled the NIS add ons to the IE8 toolbar except for Symantec Intrusion Prevention . This has finally fixed the problem.
XP SP 3
NIS 2010 17.5.0.127