I got it to successfully update the firmware.
I'm running a MAC mini with vmware running windows XP.
I navigated to the firmware update, held the "+" key and tapped the firmware update area and I got the confirmation screen.
I confirmed while holding the "+" button and the screen went blank - no further messages.
I started the Cubex windows application.
I plugged the Cubex into my MAC and directed the USB device to Windows.
It detected the device,said it installed it & I declined the reboot.
I tried the Firmware update button from the Windows Cubex application and it let me select the firmware to load and successfully loaded it.
I then had to turn off the Cubex and re-start it.
It made me re-activate it.
After that, it was ready to go.