wrong instrument selection

Hi,
I was playing with my Yocto today and I realised when I play OH, SD is playing and when I play CH, LT is playing !
I cleared all channels then add few OH on the sequence then SD was playing, so I turned the selector to SD and the sequence was the same.
The same behavior on CH coupled with LT is present.
It seems the selector selects the wrong instrument. Is it a HW or SW problem ?
I build the yocto long time ago and I didn't notice this behavior. I'll try to open it and check this selector.
Let me know if you ever have experienced this.

sounds like hardware issue.. make a list of all 16 positions and what they do, i had a similar issue and once i did that it was quite obvious to fix (after comparing the "wrong" positions to a gray code truth table it was obvious 1 specific bit was "stuck")