Had some early lockups that only a hard reset could fix.
After downloading the latest efika.forth (hadn't seen it) I can fully appreciate the demo.
I'm guessing it had something to do with the USB bugs in the EFIKA firmware.
CBM Amiga 1200 + 4MB AMITEK with 33MHz 68882 FPU
PowerBook5,4 1024MB 1333MHz G4