CFP 3.0 incompatibity with Blue Coat K9 Web Protector 3.2.44 - hang at boot

I downloaded and installed Comodo Firewall Pro 3.0 for WinXP SP2(32bit);
later I installed Blue Coat K9 Web Protector.
After K9 was installed and the system was rebooted it “hung” just about as soon as the “boot” drivers were finished loading - even before the boot log which I’d asked from the [ F8 ] Boot Menu had been started.

I recovered my system with a Last Known Good Start, removed both K9 and CFP then reinstalled CFP.
After rebooting I then re-installed K9 Web Protector … upon reboot system hangs in the same way on boot.
Another Last Known Good startup was needed.

The CFP icon still appears in the system tray with no obvious indication
indication CPF isn’t working (because the Last Known Good Start effectively removes the Windows Registry entries for CFP’s drivers) ; one has to open CFP and check the Status sheet to see it’s not working.

I like K9 for its ability to give me a heads-up about “bad” download sites and its ability to filter advert servers.
( flames over filtering ads to NUL: please :SMLR )