[jeremyroberts]

Mark,

Please pardon me if this sounds too basic, but do you know how to view mute automation in a track?

On every track, you can view "waveform" or "volume" or "mute" or "pan" or plugin automation data. Do this from the edit window - per track. I guarantee that you have an automation breakpoint written in for tracks 2-4.

When Rail referred to automation, he meant breakpoints have been written. It has noting to do with enables, or mode, or anything else... one way to check if this is so -- set all tracks to auto-off (option-click on "auto read" in the mix window). Do your mysterious mutes happen now? Of course not. Delete the mute writes and you'll be fine.