David posted this on his blog after bumping into the issue himself and discussing it with support.
“Thank you for choosing Autodesk Support.
Internet Explorer 8 is not recommended to be installed when used with Revit 2009 64 bit. There is a known issue with the recent files screen. The Recent Files menu is an HTML based window and uses Internet Explorer and has not been designed to be used with IE8.
IE8 is also not recommended to be used with Revit 2010 as it has not been designed or tested with it. The same problem does not exist with the recent files screen in the same way but it is apparent that if you have the recent files window up and TAB+CTRL between your windows while using 64 bit and IE8, it will crash. You can use IE8 if you do not have the recent files window open.”
I know that I really don't care what IE is doing because I've been using either Google Chrome or Firefox for quite some time. The only time I have to use IE these days is when some embedded IE/Autodesk feature doesn't work in them. I hope that it doesn't become an installation requirement at some point to use it in order to use Revit etc.