I don't have a way to test IE, but this issue resides within your browser, not the feed itself. I tested your feed in my browser (FF 2.0 Mac) and it works fine
In FF 2.0 I get a stylized rendering of the feed with a subscription option...this was a new feature within ff 2.0 and versions prior to that just rendered out plain xml.
do other rss auto detect links work as they should?
i should say more clever stuff