Not sure if this is any help - but I noticed similar situations on the SD1 and found different sets of midi messages recorded on the master track that I don't know how they got there - but volume changes were part of the problem. I just started deleting random things and sometimes the problem got solved. There seems to be some proprietary anomalies with the SD1 sequencing system that drive one crazy. Track and channel assignment complexities for one.

MikeH