If I remember rightly, you don't even need a AIC (CMI-07 the Analog IO card) card to run the system. I never had one in my system.
Rob pointed that out earlier in the thread. In my local build I've disabled the SMIDI and AIC boards, and it at least doesn't cripple performance when the system disk hangs, but it's still mighty displeased about something.
I'm adding more verbose logging to try to nail down where, perhaps, it's going wrong.