I switched to IE (which is never ever used), and it worked.
Then I tried Firefox again, and lo and behold, it worked.
But then I went to Home page, and could not get back to /forum/ without typing it in manually.
Then after that manual entry, then my own home page link still worked, so long as I avoided the Home page here.
Never was a problem until this evening.
NOT FULLY TRUE. If I click the forums menu, it gives the me only the home page, and it is hung in that loop again. Typing /forum/ works.