SimCity 3000 and Iomega extensions conflict?

Vincent Minnella was getting numerous system freezes when running SimCity 3000 on his G3/BW (OS 8.6). A few other readers (including Erik Goetze) have reported similar symptoms. Vincent writes: "The problems manifested themselves in failure of the SimCity sound and/or system freeze when selecting in the main menu. There is also a freeze when using 'Save...' or 'Save as...' while in the city mode." Maxis-Electronic Arts Support advised him to disable all Iomega extensions. This eliminated the symptoms!

More generally, Jonathan Morris notes: "It says in the documentation for SimCity3000 to run with just Mac OS Base extensions."