Key Inputs to CDU via OC Keycard

Hi All,

I'm having a strange problem with the key inputs from my CDU to the PM CDU software. I have the hardware CDU connected via an Opencockpits USB Keys card and when I direct the output to a notepad window for testing all works ok, all key inputs correspond to what I expect in the notepad window i.e. A on the CDU press makes A appear in the notepad etc.
When I redirect the output to the PM CDU window then strange things are happening, all the LSK/RSK inputs are fine, all numeric inputs are fine (i.e. appear in the scratchpad) and all the DES/INIT/MENU etc keys work ok but I am unable to enter any alpha keys, e.g. if I press A then nothing appears in the scratchpad, this is the same for all alpha keys except O which when I press this changes the display from screen only back to screen and keyboard.

Any ideas anyone?

Cheers
Mike