Long story but I'm creating accounts using RoleMembershipHelper.CreateForumUser(user, displayName, 1) rather than directly within the forum's own registration functions.
All is working except that though I can see the DisplayName field in the yaf_User table is being populated, when you look at the forum pages, everyone is referenced via their username rather than the DisplayName. Is this a flags thing? Or UserStyle? Bit stumped and any help much appreciated.