Charles & Sandra Cohen
a) If you can control the baud rate, run the interface and the rig at a low baud rate. Sometimes that helps. There's a "CI-V Baud Rate" setting in the IC-7000 menu, item 48.
b) If you are transmitting with the IC-7000, the USB cable is _very_ sensitive to RFI. Put several ferrites on it, and if possible, coil the cable through the ferrites (i.e., use the ferrite as the core of a toroidal inductor).
If you're not transmitting with the IC-7000, (b) is irrelevant.
. Charles / VA7CPC