File download over HTTP in IE

I am experiencing problems with file downloads (in my DNN module) in IE over HTTPS. It is a known problem in IE (Microsoft support) and I found many related articles, like the one here. The post suggests not touching the cache settings fo开发者_如何转开发r a secure connection in IE. But our code has always been using HttpCacheability.Public.

Response.Cache.SetCacheability(HttpCacheability.Public);

Although, when I inspected the headers for the HTTP response in question, it shows

Cache-Control: no-cache, 
Pragma: no-cache

How else can these values be controlled?

It turned out that the customer's host settings were over-riding the module output. changing them helped.