Did you create a listing using the id90 website after you purchased your ezed on myidtravel and then use the id90 issued pnr # to try and check-in online? I've traveled on US & DL using electronic zeds purchased on my idtravel from jetnet and have never had a problem. I've only used a zed on UA once but that was when they still had paper zeds.

I believe the lap child only becomes an issue for international travel in which case, you need to check-in with an agent. Still, it should not take an hour.