same problem here. DEP is enabled for all programs. Tried both suggested ways to enable it, restarted both times, verified settings (start bcdedit as admin from cmdline - see last line - nx is alwaysOn, started APB - same problem "enable DEP, APB will exit now"
I am on win 7 ultimate 64 Bit. Maybe some trick with adding a custom manifest resource to the apb executable works? Or maybe the new anticheat will instantly go mad and ban me, my mum and my hamster