Drum track with SMP24


I use a vintage installation: Atari Falcon 030 + Cubase Audio 2,06 + SMP 24 my last purchase recently.

I have a strange matter : If I declare the channel 10 as a Drum track, whatever the MIDI port used, no command reaches my expanders and so I have no sound. I must transform the drum track into a MIDI track to ear something. No problem for recording as Drum track but with no sound.

Someone could explain this strange affair ? Thank you.