I just received my brand new I140 and my system is doing the same thing. After I installed iCue (that was NOT preinstalled on my system), I linked my K70, Ironclaw, Void Pro, MM800, and ST100 to Spiral Rainbow. A few minutes later I started getting the constant USB connect/disconnect sounds with the associated case lights going off, coming back on blue, then starting the rainbow sequence again.
A reboot seems to temporarily fix it.