It seems we found some problems recently with some of our intranet websites.
When the page loads on one computer with IE9 the rendering is very slow (more than 2 minutes). If the page is loaded with firefox on the same machine, it renders almost instantly.
We tried on another computer with IE8 and Firefox 4 and IE10 beta the page loaded almost instantly also.
Another test we've done is to load a website on the internet with IE9, it loaded very quickly. It seems the problem comes with IE9 and Intranet (but not all of them).
What could be the reason behind that ?