There is a WARNING on another forum that I belong to, about some strange behaviour by IE7 -
IE7 has been launched by Microsoft and already people are finding that thousands of websites do not work in the new browser.
We do not know whether the website or the Forums will work in IE7 and it is our strong recommendation not to download it until more is known.
Worryingly, Microsoft are planning to include it in Automatic Updates sometime in November. This may well cause a Millennium Bug like meltdown, as people discover web-sites and web-based programs that do not work. Our advice is to reject the automatic update when it is offered.
I don't know the facts of the above, but it's from a usually very reliable source. I avoid IE like the plague after a very nasty virus infection a few years ago. Firefox works fine on 99.9% of websites: those that say "only MSIE can be used on our website" just don't get my business.