Preventing temporarily allow IPs on .htaccess

How do i prevent a programme from adding lines of code to .htaccess which allow the same IP address to revisit the password protected directory without having to log in again?

This is being generated by the membership software and added to the end of the .htaccess file

AuthUserFile /xx/xx/xx/xx/xx/xx/domain.co.uk/public_html/xx/.htpasswd
AuthGroupFile /dev/null
AuthName "Only approved member access to this directory"
AuthType Basic
<Limit GET POST>
require valid-user
</Limit>
Order allow,deny
Satisfy any

#|test889|13348283908|Allow
Allow from xxx.xxx.xx.xx

removing it means it performs exactly how I need it to, but it regenerates each time a new log in takes place. Log out also won't work because of it.
There's a setting in the admin panel to adjust number of IPS stored here and I now have this set to zero, but they are still being written. If I can't prevent it from being written (which it seems i cant) then is there a way that I can prevent it from taking effect?