I recently had an issue sending the right headers to let IE8 know to go ahead and download a file, in this case a PDF. If you’re running into the same issue, make sure you send the following headers, at a minimum:
Pragma: public Expires: 0 Cache-Control: private
And then finally, your content type header:
Content-Type: application/pdf
This should cause IE8 to download the file. If you want the PDF to open up within the browser, make sure to include the following header:
Content-Disposition: inline
Adding these headers shouldn’t cause issues in any of the other browsers.