When accessing http://forums.microsoft.com from Internet Explorer or Visual Studio 2005 Help/Search/Community, you might get a runtime error or the page seems to be loading constantly.
This is due to status codes 500 Server Error or 307 Redirect.
Unfortunately, the 307 redirects to the same location, which is, in fact, an HTTP protocol violation, so from other browsers you might get an "invalid redirect" or "protocol violation" as well.
Delete the microsoft.com cookie. For IE6: Control Panel, Internet Properties, Temporary Internet files, Settings.
Now, try again.
You have to "Sign-in" again, though. [Update: Do not use the “Save email address and password” option!]
This post was brought to you with the indispensable help of Fiddler2, a Web Debugging Proxy and extensible HTTP analyzer by Eric Lawrence of Microsoft.