best way i did to avoid this was to edit the source of the plugin and make it admins1.cfg and admin_groups1.cfg so it kept the others intact for more broad use.
This won't get them loaded though. It's one of sourcebans' worst behaviour to overwrite user files /slap asherkin
You should set "BackupConfigs" to 0 in your sourcebans.cfg to stop it touching the admins and admin_groups config files.
Threaded Mode