Can't display PDF from HTTPS in IE 8 (on 64-bit Vista)

Thought I'd come back and give the final answer.

Thank you to everyone that suggested "Do not save encrypted pages to disk".

I followed EricLaw's advice and set:

Cache-Control: private 

I also found that I had Pragma: no-cache, which I removed.

Works like a charm now :)

I ran into this same problem, and could only get it to work by asking the user to modify their security settings to turn off Do not save encrypted pages to disk in the Advanced tab of the Internet Options dialog: http://support.microsoft.com/kb/812935

...then with the immediate panic over, I started looking at the code (ASP.NET using VB). I used fiddler and found that even when I wasn't specifying the cache-control header it seemed that the Framework was automatically specifying no-store for me. The key to solving the issue was actually in this PHP question. By setting the cache-control header to max-age=1 the file would be cached for 1 second, just long enough for Adobe Reader to pick it up from the disk and load it into memory. I updated our code to generate the PDF as follows:

Response.ClearContent()
Response.ClearHeaders()
Response.AddHeader("cache-control", "max-age=1")
Response.ContentType = "application/pdf"
Response.AddHeader("content-disposition", "attachment; filename=whatever.pdf")
Response.AddHeader("content-length", mem_stream.Length.ToString)
Response.BinaryWrite(mem_stream.ToArray())
Response.Flush()
Response.End()                                

Update: I thought it was working, but I guess I spoke too soon. I created a new question to follow through with this issue.

response.setHeader("Cache-Control","private");

did the trick for us in IE8 and IE9.

That did not require changing settings in the browser.

I had a similar problem with IE8 and https. When I tried to stream a pdf to a new window, I got a blank html page instead (it worked in FireFox and if it wasn't via https). After a lot of searching and trying different variations of the response headers, the solution for me was to set:

Response.AppendHeader("Accept-Ranges", "none");

This downloads the whole pdf before it opens which is less user-friendly if it is a very large pdf. But in my case most pdfs were only a few pages. Hope this helps someone out.