The reason why I published this link is because a coworker had a problem with viewing a PDF on IE6 when the cache was set to no-store over https.
The problem does not happen with Internet Explorer 7 or above or with FireFox, but the old IEs fail to retrieve the files when the cache directive is no-store or no-cache.
More of this on:
Internet Explorer file downloads over SSL do not work with the cache control headers
Unable to Open or Run Files if “Cache-Control: No Store” Header Set
and
Prevent caching when you download active documents over SSL
And another good reading on Caches on the web: