Like stated without knowing more what group this is I cant respond more definitive but you need to view this user in vb
and see what group he is in. You can either move this user to some other vb
usergroup that has posting priviledges or as noted in photopost edit usergroups you need to set priviledges as you wish for the various groups.
Since your integrated with a forum users usergroups and info have nothing to do with Photopost we only assign permissions based on a users usergroup. Most likely if you used vb
's impex script to import user info from some other forum they users groups might be imported groups not the normal usergroups.