The supplied Cubasis is a really older program, and what you're describing might be a conflict of Steinberg stuff more than anything else. What sort of error message are you getting and what OS are you running?
I'm sure that it is a Steinberg conflict. When I first couldn't get AI-4 to recognize KP-2, I uninstalled it, and tried to re-install Cubasis. Cubasis installation barfed during the copying of files. Apparently there is something buried in the Windows XP registry that was installed with AI-4 that is causing the conflict.
Now that I have AI-4 installed, projects that were created with Cubasis are rejected by AI-4, so all that work goes down the dumper. Thanks Steinberg.