This is really odd but it has happened with these two forums in both IE7 and IE8 Beta far too often to be my imagination.
If I go to the MSDN and TechNet Search forum (
http://social.technet.microsoft.com/Forums/en-US/SearchFeedback/threads/) or to the TechNet WebSite Feedback forum in the same set of forums (at the very bottom of the total forum list at social.technet.microsoft.com), then the back button in the browser vanishes.
All other functionality is still available. I can still write messages; amend posts; move posts; click on the breadcrumbs to move elsewhere, it's just that the back browser button isn't there.
(I am located at the total list of TechNet forums when I go to these forums).
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I haven't checked this more than once but if I first go to one of the other forums from this set of four (where the back button is still visible) and then go to one of these two forums, then the back button in that test case *was* visible.
