HP 41 Card reader problem

[Cancuino]

I've tried another module on the 4th port and it works fine.

I have only one HP 41 and it's in a pretty good shape. With the card reader attached and the calculator off the motor doesn't move at all. If I try to turn it on, sometimes it does and sometimes doesn't. When it does it recognizes the card reader but if I list the functions in it, it usually freezes.

Best regards.