We recently upgraded from ActiveForums 3.7 to 4.3.4 (in multiple steps).  Somewhere in that process the User Display Mode got set to Username (was set to Display Name).  While this would not be a problem for many sites, we use the e-mail address for the username on our site, so suddenly we're making e-mail addresses public.  Not a good thing.

Ok, so we switch the setting on User Display Mode to show the Display Name and expect everything to be ok, only not quite!

It seems the name of the last authors to post in each forum are stored in the forum records, which are not updated to reflect the setting change.

Here's a SQL script to update that table to show display names immediately:

UPDATE dbo.activeforums_Forums SET LastPostAuthorName = DisplayName FROM
dbo.activeforums_Forums f JOIN dbo.Users u on f.LastPostAuthorName = u.Username
WHERE LastPostAuthorName like '%@%'

(run this from Host/SQL)