Got it test running on one networked machine, where it seems to be doing the job without any problems. I had it on another, but it had a dial up Internet connection and Cyberhawk would keep trying to dial back home to check for updates. The only way to stop it was to turn off the update facility and as it has no manual update option this seemed counter-productive. In this case removal wasn't problematic and didn't leave any registry junk.
So while it's got a few design idiosyncrasies that I don't like, I've not found it problematic and I suspect that your app conflict theory is correct.
Reading the site is odd as they seem in one breath to suggest it's superior to other more traditional signature based AV programs, Yet the FAQ page says:-
Since no single application is currently foolproof, Novatix believes that a layered defense provides the most complete protection. Cyberhawk is the perfect complement to your existing antivirus, and will protect you between antivirus updates. It is fully compatible with traditional antivirus programs, and can run side-by-side with these programs without conflict. While the traditional programs will protect only against known threats included in their signatures, Cyberhawk goes beyond and protects against new or unknown zero-day threats as well.
Which makes it look as if they're hedging their bets.
I think it's an interesting product, but will be fascinated to see if it gets tested by ICSA or VirusBulletin, as anonymous customer testimonials are a pretty lousy reason to use a product. I will keep the test set-up running and watch for other more informed opinions than my own.