Duh.....  In my haste to get things working I neglected to reboot the PC after reinstalling the cable driver. Seems to be working fine now on the V8000. And I was using the wrong cable. I have two cables: one with a 1/8" mini that plugs into the speaker jack and one with an RJ45 that plugs into the mic jack. I could've sworn I used the RJ45 on the V8000 last time. Its working now with the 1/8" mini in the spkr jack.

Now I'm about to try the one with the RJ45 in the F121 out in the mobile. Cross your fingers. And thanks for not laughing.   Sometimes I'm surprised I can tie my own shoes.......

Yup. Did that, too. Device Manager showed it to be the same, Comm 4, that the software shows. I even tried changing it in Advanced Settings in Device Manager to Comm 3 and then changing it in the V8000 software to match. No dice.

Thanks for the quick reply, though. I'll keep working the problem.

Of course, now that I have my new ham license my Icom is giving me fits. I have had an IC-V8000 as a base station since last winter. I programmed it with the Icom software and OPC478 or OPC1122 USB cable but now that I want to reprogram it and remove the transmit inhibits for the 2-meter repeaters around me, my cable has quit working. I've uninstalled the driver and reinstalled the driver, downloaded the latest driver, tried the other cable that plugs into the speaker jack instead of the mic jack, reset the comm ports and tried all four, reset them in Device Manager and again tried all four... What am I missing? How could my cable go bad just sitting on the shelf for 8 months???

I know you can do it manually but I have lots of channels to re-write. I paid good money for OEM software and cables and it burns me that I can't use them now. Does ANYONE have any ideas or experience with this radio? I would post to the V8000 forum on RadioReference.com but I've never gotten quick answers there...

Thanks.