I am using the free version of Comodo Firewall, Version 3.8.65951.477 without any problems (WinXP32Pro SP3, Logged in as administrator, Comodo Firewall Level: safe mode, Defense + Security Level: disabled).
After upgrading to the latest version of Comodo Firewall, I couldn’t start any 16-bit software (explorer memory error).
I restored my system and retried the update with the same result. After deinstallation of Comodo Firewall all my 16-bit software runs again (e.g. catfish [database software}).