2 Boards Output mirrored

Velleman IO Boards
1

Hi,
I have 2 P8055N boards.

when I execute the following code on board 1 (address 0) the output 1 is set.
Thats ok.
But on board 2 (address 1) the output 1 and 2 are set.

MsgBox (“set output”)
CardAddress = 0
h = OpenDevice (CardAddress)
h = SetCurrentDevice (CardAddress)
MsgBox (“address0:” & h)
SetDigitalChannel (1)

     CardAddress = 1
     h = OpenDevice (CardAddress)
     h = SetCurrentDevice (CardAddress)
     MsgBox ("address1:" & h)
     SetDigitalChannel (2)

what am I doing wrong?

DLL version 5.0.0.0