I implemented this code bit. Very nice find indeed.
I did find some issues. IE works flawless. FireFox however doesn't like it so much and may be the reason some say it doesn't work. They are using Firefox.
Another issue I found was that i used this surrounding a table in my header and in Firefox is distorted my header. So i get performance boost in IE and not in FF with a bug in FF that prevents me from using this.
So I put this as a fix and wanted to share with others if they experienced Firefox bugs because it resolved my issue.
Code:
<!--[if IE]>
<div style=" overflow: auto; "><![endif]-->
Your header or footer
<!--[if IE]></div><![endif]-->
Even though FF users wont get the benefit directly, the load reduction on the server from IE users will spread the wealth to FF users.