the init.d scripts are just the ones to start your daemons.
For start sth. on boot you have to take a look in
where * is your runlevel. The standardconsole one is 3.
There shoud be a symlink to the init script from init.d
Don't know chkconfig on Suse but on RHEL/CentOS/Fedora you are able to define in which runlevel the script should start.... if you don't find sth. like this,
just install a symlink in your /etc/rc3.d/
ln -s S99ispconfig_server ../init.d/ispconfig_server
ln -s S99ispconfig_tcpserver ../init.d/ispconfig_tcpserver