Then post in International Help Forum:
http://www.ioftpd.com/board/forumdis...?s=&forumid=13
ppl get banned for connecting x times inside y seconds (defined in your .ini), not for connecting more that their allowed limit.
you can't define a specific login limit for a group, only per user and default (ioftpd\users\Default.User).
no bug there, configuration problems.