Pick & Mix Macbook: Keyboard Issue

Hello
i have just replaced my core 2 duo white macbook keyboard with a core duo white macbook keyboard (previous gen) - due to water damage...

fortunately the keyboards appear to be compatible with both core duo and core 2 duo -

However

the trackpad "click" button does not work :s - urgh - and i dont know whether this is due to using a keyboard not intended for my model or simply due to a keyboard error - is there any way i can check this using some sort of diagnostic tool?

thanks