I think this has come up before. I can't change the forum default, would need access to the Control Panel for that, "Which in this case we have not got," as the poet said.
Members should be able to change their own settings though:
USER DETAILS - Settings (Profile) - Order of Topics (select from drop-down list). Then "Save Changes".
The screen is shown in the attachment below.
-- Edited by Rectalgia on Tuesday 23rd of October 2012 08:05:57 AM
Noting - whichever method members might use to review current posts - there is often some delay before the "invisible" anonymous "Pending approval" posts and misidentified "Spam comments", similarly hidden, are noticed and "released" (approved) which is why PDA has taken to adding a current comment to "bump" them to the top of the listings when found and which I (as always, lagging the field) have started emulating.