It looks like the most recently updated thread moves to the top

[Gareth]

Edit:  Found the solution, instead of messing with the sorting order in the column header, go down to the bottom of the displayed threads and there's a three pop-up menus and a "go" button.    Set them to "Sort by: Creation Time",  "Order: Descending", "From: The Beginning", and press "Go"

That works, but it doesn’t stay that way. You have to re-sort each time you view a thread, unless I am missing something.

Yea, the setting doesn't hold across sub forums (i.e. if you switch to Political), but it is included in the URL, so I updated my bookmark to include it, so at least when I use the bookmark to visit the forum, it's in Creation Time order.