Cannot connect to 4424 - Windows 8.1 Pro

Hello,

I have been using a 4424 with Windows 8.1 Pro (HP Envy tower PC) for a while now and even though it was flaky, it was usable (I had to plug in/out several times to recognize the device, and it would occasionally freeze).

I just upgraded to 6.8.10.13 and I can no longer connect to the device. I have tried to re-install (fix installation), rebooted several times, used all the built-in USB ports, used a powered USB hub, not nothing appears to work.

When I unplug/re-plug the device, the s/w pops-up the 'Opening devices' dialog box, the red light on the device blinks once, but it can't find it.

I uninstalled the s/w and then installed version 6.6.57.20, and I am back operational, (without even a re-boot).

Not sure if others are having similar issues with 6.8.10.13, but it did not work for me.