Facebook doesn't like IE8
<sigh> This is what happens when the code used by a web site to detect (and adapt to) different browser versions is not properly written. According to Facebook I am running IE6 - I'm not, I'm running IE8 Beta 2 (as you can see from the screenshot).
If I view the Facebook site using Compatibility Mode, the problem goes away. Compatibility View simply changes the User Agent String from:
User-Agent: Mozilla/4.0 (compatible; MSIE 8.0; Windows NT 6.0; Trident/4.0; SLCC1; Media Center PC 5.0; .NET CLR 3.5.21022)
User-Agent: Mozilla/4.0 (compatible; MSIE 7.0; Windows NT 6.0; Trident/4.0; SLCC1; Media Center PC 5.0; .NET CLR 3.5.21022)
There is an article on the MSDN site that explains how best to detect Internet Explorer versions. By using Conditional Comments you can code your web site to recognize a particular version of IE and later versions, which is infinitely preferable to coding a site so that it only recognizes up to a particular version (a subtle but important distinction). Obviously, if a site is coded to only recognize up to a particular version, the site will be unable to recognize any newer versions that are released and may misdetect it, as has happened in the case of Facebook.