Philip,
Thanks for the reply, good to see I am not the only one who has had this issue.
I do not think it is the USB 3.0 side. I can run my home made cable using a 2 meter USB 3.0 extension cable. So it must be the speed the signal travels once it has become analogue after the FTDI convertor.
I tried the new cable in a powered hub, usb2 port and usb3 port directly on the computer.
You are correct the baud rate can not be changed, it stopped the computer even seeing the mount on both cables.
I also wonder due to them being a moulded DB9 connector if the pin out is exactly correct for the application we need. I noticed like my home made cable that the real shoestrings are terminated with a non moulded DB9 connector. This makes me think there must be a reason behind the fact they solder their own connections.
More money wasted
Thanks
Carl