Anyone use the Bendix King CDU addon?

Nice addon this. I am using it with the TDS b787.

But can anyone say, why when I have entered cruise altitude then select Calc Vnav and EXEC, all my airspeeds are still blank. The flight plan looks OK otherwise, but the entries are all like this: ---/FL290; ---/FL390  and so on. I have to add the airspeeds manually for each waypoint to get VNAV to operate correctly. The guide says they will be calculated automatically.

Thanks,

Martin