Ok, I've done some additional testing moving zones around, etc.
Would love it if someone would please follow the below repro conditions to see if it's just me or if this is a problem in 603.
1. Setup some zones (doesn't seem to matter if they're default zones or user created) and point them at a connected DAC.
2. Mute the first three zones in the zone list (either through the button on the Zone Settings General tab, or through the APC40's mute buttons.
3. Switch preview window to show grid of 9 Zones (or any grid setting showing more than one zone). You should see the first three muted and the remainder not muted.
4. Select one (or more) of the first 3 muted zones (by ctrl-clicking the preview window, or using the zone select buttons on the APC40)
5. Run a cue in a selected (muted) zone. Note that the preview window will not show the running cue until that zone is un-muted. **in my setup the cue's default zone always points to a zone without a connected projector. This is how I ensure a cue ONLY plays if a zone is first selected.**
Prior to 603 (was using 588) preview windows will show cues running in them even if they're muted. Afterall, that's what preview is all about, seeing something before you unmute it for the world to see.
Also notice that if you have zones 1-9 muted, place cues in them and then switch the preview window back to single view (no grid) that all cues will show even though they're playing in muted zones.