Fs key problem

Hi,I add the third fskey card (CID 3 )to my fsbus system. But there is a problem:No problems with separate switches, but when I add a 12-stage rotary then strange things happens.Turning the rotary,for changing the nav1 freq.,sets the spoilers to 100%, flaps goes down,N1 increase.No matter on what RID I connect the rotary.Chanched the nav1 for comm1 or another, same problem.Chanched the rotary for another, same problem occurs.Any idea what can cause this? Bets regardsJan Geurtsen