I just updated the firmware on my Z. Word of advice: when you have everything hooked up, go to the Windows Start menu, select Devices and Printers, and click on the Z icon on the bottom and note the COM port it is connected to. I completely spaced and missed that there was a menu selection on the flash utility and tried to program over COM1 (the default) about 3 times before I did this and saw the device was on COM 3.