One additional piece of info for what its worth. Using my code editor, I did a search for occurrences of "threads7" in the version 2.6 files and in the version 3.1 files. One difference I found was that the file adm-inc.php in the version 2.6 file has a call to "threads7" like this:
Code:
Content visible to verified customers only.
But this reference is not there in the new (3.1) adm-inc.php file. No idea if this is relevant to my problem, but I thought I should mention it.