Now this is weird.
I have the mod in place and can see all the latest posts (as admin). If I log out (to guest) the list is blank, even though guests are permitted to see almost all the posts in the forum.
If I log on as a regular user, the list is indeed blank (doesn't even contain posts I made as that user!).
If I log in as a member of a private group that has access to a private area, I can see the list again - but, the first visible ("latest") post is a post made by that member in the private area - ignoring a more recent post made by a regular user in the public area!!
Methinks the replacement default.asp page isn't quite perfect...