Help! MZ-M100 creates unwanted tracks
 

I believe I've read about every word in the instruction booklet, and visited about every menu option, but this #@*& thing still creates 30-70 tracks during a 1 hour or so shoot in PCM mode when I want one track. It makes for a workflow nightmare.

Does anyone know how make this thing behave?

[Edit: I didn't mention that I was recording from a board. Looking more closely, apparently the M100 creates a new track every time its input gets muted, and I don't see any way to defeat it :>(