I am also having this issue with my new TX Nandx Usb update cable
I have tried
3 Laptops Win7, Xp
2 Desktops Win7 and Xp
with both powered and non powered usb
Un-install and reinstall of the applications and drivers.
Tried all baud rates, changed com ports, 12 and 14.745.
Attempted with both LPC2000 Flash ISP Utility v2.2.3 (Just hangs) and Flash Magic (always returns the auto baud error).
I am going to try and play around with the reset button and see where I get. If anyone has any ideas I can try I would appreciate it.
Thanks