iPHONE: Why doesn't the Overdrive app remember my card number even though I checked the "Remember me" box last time I logged in?

Q: Why doesn't the Overdrive app remember my library card number even though I checked the "Remember me" box the last time I logged in?

Please read these instructions (PDF) and follow the steps. Then log back onto OverDrive and check "Remember Me" again. The selection should remain from session to session now.