[apologies, I put this on the dev list but should really have put it here]
IE8b2 will crash if you try to insert a text node after a float. This might not seem such a common thing to do, but remember that jquery parses html into nodes before appending - and if your html starts with a space then the first inserted node will be a text node and kabooom! I've put up test page here: http://partyark.org/html/ie8floattest.html This completely shafted my site (http://www.partyark.co.uk) where we use jquery to write a 'basket summary' div at the bottom of the page if you've got something in your basket. What with this and lack of opacity I've had to put up the IE=7 http header thingy until they get this stuff sorted out.