Is this an Iomega Mini Max you are referring to?

I did not install MorphOS 3.3, I just manually/individually added/installed the newer features of MorphOS 3.3 in one-by-one, onto my MorphOS 3.2 installation, and only the ones I needed, as I too have a MiniMax, though I also have a Belkin 4 port USB hub, and a Belkin 2 port Firewire hub which also has an additional 4 USB ports, so I have 13 USB ports and 3 available firewire ports.

If you are having problems with MorphOS 3.3 with such hardware I am glad I installed the items the way I did onto my Mac Mini 1.5GHz MOS 3.2 system, as my system works as it did with MorphOS 3.2, and Mac OSX.