New CH Eclipse Yoke and VOX Atc

I bought the new Eclipse yoke to replace my faulty CH Yoke which had given me good service. The yoke works fine except with VOX ATC.
My computer runs Vista 64bit. When I try to Set Up the Joystick for VOX ATC the screen that appears has options to assign buttons.
When I click ASSIGN PRESS TO TALK it should grey out and give me the option to select a button to press for this function. It does not. In the Joystick box the CH Eclipse Yoke appears and in the button box is 23 but I cannot change them nor do they work.
In contrast the keyboard works fine and when ASSIGN PRESS TO TALK is pressed it greys out and I can change the button assignment.

To see if my desktop was the problem I installed FSX on my laptop which runs Vista 32bit but I have exactly the same problem with VOX ATC.
The Game Controller in the Control Panel shows all buttons, keys and axes work OK.

I am in touch with VOX ATC technical help who are looking into it but just wondered if anyone else had a problem with this setup.

Simmy