I use win98 and ie 5.5 and have never had a browser crash on 6.0.1 or 6.0.2
I have also never gotten any crash complaints from any of my board users.
Are these people who are crashing using some 'hacked' version of IE, such as one from AOL or one that comes installed on a computer and is altered by the manufacturer? In my experiences, most versions altered by others than the creators are unstable. Even if you upgrade off of a hacked version, it will probably leave behind stuff that will make it unstable.