Sorry for the delay in getting back to you. Things have been busy.
So, the outdoor gig was last Saturday night. The dropped connections were happening again, but with both iPads, and at the same time with both. In fact, when Master Fader disconnected, Airplay also dropped out. That made me think the router may have been bad. And, since I have a large gig this weekend, I figured I better get another router. So, I picked up another Airport Express, and installed it in my rack with the DL32R. Yesterday, as we were setting up for this weekend's gig (a 9000 seat arena), everything worked flawlessly. But when I powered everything up this morning, it started the disconnects again. So I restarted the router, and everything's been fine since then.