Internet Explorer file downloads over SSL do not work with the cache control headers

We force SSL in an extension using SSLZones with: ModuleViewAccessMode[membership/*]=ssl

Firefox can download the PDF with no problem but IE can't. If I remove this rule then IE7 is able to receive the file successfully, otherwise the user gets the message "Internet Explorer was unable to open this Internet site. The requested site is either unavailable or cannot be found. Please try again later."

Some references that may be helpful:
http://support.microsoft.com/kb/316431
http://support.microsoft.com/kb/323308