I’ve never had any problems with either of those AV’s installed with Comodo Firewall. Enter Kaspersky as trusted with Comodo defense and enter Comodo as excluded in self protect by Kaspersky. Same with BitDefender.
Some don’t like CIS’s firewall, because maybe it has bugs for them or is not user-friendly enough.
It’s not as easy as that, Kaspersky is incompatible with Defense+. You will need to disable specific components of both to let them work together…
eXp
I ran Kaspersky for one year with Comodo Proactive Firewall and never had and incompatibly issue with Kaspersky and Comodo Defense +.
Almost forgot this; You have to install Kaspersky first and then install Comodo (Comodo will have to be put in training mode before the installation reboot).
If I had the time and just to prove a point I would download an install Kaspersky with Comodo v4 and throw in a twist and add ESET NOD32 and Outpost Firewall to the installation. All four apps running with there settings at there highest level (No components disabled) and running with no compatibly issues.