I have a web application which displays pdf's in an IFrame. I recently made a change to start serving up the PDF using Django instead of allowing Apache to serve the PDF. Initially, I used the FileWrapper approach to return the file. This worked fine on all browsers except for IE 8 which crashed (maybe other versions of IE, didn't test).
I figured out how to fix this but it was a bit of a pain to figure out so I am posting the answer here.