I'm super busy with preparing the beta release of HelpSpot, but I wanted to post about a tool that has really saved my butt. If you need to debug IE and/or IIS then you need IE Watch. It's a great IE plugin which shows you all the back and forth headers IE sends and receives. It's really helped me out a lot, seeing where IE caches when it shouldn't and all the weird things IIS does. Good stuff.

http://www.iewatch.com/