If you want to post about this in the Help section of the Firewall forum, someone will help you. CPF does not have to be disabled in order for ICS to work. There are just some rules to create in order to allow it.
I just wanted to make sure you were aware that ICS will work with CPF. In addition to the Network Rules needed for the computers involved, I understand that you have to allow multicasting (IGMP) protocol between them in order for ICS to work, which will require an addition network rule.