Fix: 503 Service Unavailable when accessing content on Windows Media Services 2008 server behind load balancer

I have three Windows 2008 Media servers that I’ve had issues with getting to work behind our F5 BigIP load balancer.  When we took packet traces, HTTP GET requests from the Media Player client have been responded to with 503 Service Unavailable.  

You can read all about this particular issue at the Random on Window Media blog.  The solution ended up being applying the KB960372 hotfix, which was apparently released March 13, 2009.  The hotfix KB article doesn’t exist as of today, but Random’s post suggests it will show up eventually.
[update 04-08-2009]
KB960372 is now available.
The WMS 2008 x64 hotfix can be found at