Since I normally set my firewall up once and seldomly do a change here,
I don't use the ISPConfig frontend for the firewall.
I use firehol for that (
http://firehol.sf.net), a shellscript which creates all iptables stuff with much flexebility from a configfile. It is very fast to setup.
Another good thing is, you can "try" new configs which gets discarded if you don't commit them after 30seconds to prevent beeing locked out from ssh...
I use that on on Linuxbox at home where I also use smb... no problems yet...