Linux IP Masquerade supports CuSeeme via the "ip_masq_cuseeme" kernel module. This kernel modules should be loaded in the /etc/rc.d/rc.firewall script. Once the "ip_masq_cuseeme" module is installed, you should be able to both initiate and receive CuSeeme connections to remote reflectors and/or users.
NOTE: It is recommended to use the IPPORTFW tool instead of the old IPAUTOFW tool for running CuSeeme.
If you need more explicit information on configuring CuSeeme, see Michael Owings's CuSeeMe page for a Mini-HOWTO or The IP Masquerade Resources for a mirror of the Mini-HOWTO.