I have exactly the same issue with zone 2. For now, I have configured as follows: plugged DC trigger for main zone into "trigger 2" output on the 990 and programmed only 2 video sources to turn on the main zone amp. Not ideal, though, if I want to use one of the other sources in zone 1. (usually Zone 1 only uses these 2 sources, but not always). My amp allows a manual switch over-ride of the trigger state.

I haven't tried it yet, but in contacting outlaw directly they suggesetd that I connect my main zone amp to trigger two and program trigger two to activate for all sources. Thus, whenever the 990 is powered on for the main zone, trigger two will activate the amp (but turn off when only zone 2 is on). I have a separate distributed audio system for my other zones and only use the 990's tuner for zone two and thus don't want any amps triggered when zone 2 is active in the 990, but you could connect a zone two amp to trigger one and it would stay on when zone 2 is active (but also be active when zone 1 is in use).