To clear your cache: Tools->Internet Options -> Within the temporary internet files option is a "delete files..." button. Click that.
Or do this first: Reply to this thread, and on the reply to thread page, press Ctrl+F5 to completely refresh that page and see if the button appears.
If clearing your whole cache and refreshing just that page still doesn't work, view the source of the reply to thread page (View->Source) and
email it to me.