[TYPO3-english] front end user data in backend is chaotic

[horace grant]

hi,

i have a typo3 site with front end users. i have added some custom fields to
fe_users and i also use mm_forum.

the front end users shouldn't be able to register themselves but the admin
should add them manually in the backend.

unfortunately in the backend forms the front end user data gets displayed
very chaotically. there are many fields i don't need, my custom fields got
added in the forum_settings tab,...

is it possible to customize this form? i hope so. :) if it is possible, how
does this work? i would be very thankful if someone could give me some
hints.

cheers,
horace