OK, had to give up on the Icom basic driver. Change bands, timeout. Change freq, timeout. change anything at all, timeout. Hit the key, timeout. This after several iterations of baud rate and stop bit changes. I about wore my poor little mouse out resetting the radio interface.
I went back to the 735 driver, which didn't eliminate the problem, but makes it far, far less frequent. OBTW, didn't do this in LOGic 8 with the same computer and OS.
73 Doug W5GA