Are you sure it is an audio issue? Could it be an issue with midi?
Could there be a difference in midi channels, between the track's events and the drum module?
Also, are you seeing any meters move on playback?
Can you detail the routing assignments and the track setups?
If you select the midi track and trigger some events (keyboard controller or drum pad or whatever), do you get sound and/or midi activity out of SD?
Bob Bone