Firefox loading all css files referenced in conditional comments

Question

I have a regular css file plus two IE specific css files. In Firebug in Firefox I noticed the same div is getting properties from the three files.

Why is Firefox loading iestyle.css & ie6style.css?

<!--[if IE 7]>  
<link rel="stylesheet" type="text/css" media="all" href="iestyle.css" />
<![endif]-->

<!--[if lt IE 7]>
<link rel="stylesheet" type="text/css" media="all" href="ie6style.css" />
<![endif]-->

Addition

Answer 1

This should definitely be working. Are you sure there isn't an unclosed <!-- or <![CDATA[ hanging around in head?

Answer 2

Are the conditional comments in the HEAD element or in the BODY element? I haven't tried it, but it's possible that FF only ignores conditional comments if they are in the HEAD element (where they should be).

Answer 3

I think that isn't all the relevant code. Do you perhaps @include those files somewhere else?