USB: Duplicate Device Appears in Apple System Profiler

This article explains a situation where a duplicate USB modem appears in the Apple System Profiler Devices and Volumes tab. When connecting the USB modem after starting up the computer, only one appears.
This issue was fixed in Mac OS 9, as well as in the Mac OS software that shipped with the iBook, iMac (Slot Loading), and Power Mac G4 computers.

Updating older computers to Mac OS 9 will resolve the issue. Alternatively, connect the modem to the Macintosh after starting up the computer.
Published Date: Feb 20, 2012