This is fairly well publicised if you look around the Internet, but not in a single place that I could find. Hence, more for my own reference once I blow this beta build away, I'll want to get back to where I am. Certain sites don't recognise IE7 in the User Agent detection coding, and you may need to apply a few changes to make it work. Take a look at http://www.fiddlertool.com/useragent.aspx for some scripts to change IE7 to switch between IE6 and IE7 mode, and to see what your browser is exposing. Also, have a look at the IE teams great blog for more information about this topic.