I mentioned in my previous post that the X6200 creates two sets of two ports (two "cu.*" ports and two "tty.*" ports). Previously, the higher numbered tty.usbmodem port was the one that was working. This afternoon I decided to try out the higher of the cu.usbmodem ports instead (in the past, this froze whatever program I was attempting to connect to the radio via this port). Oddly enough, flrig worked with the "cu" port this time! So I'm back up and running.
--Marc nz9a