As the title states I've noticed this issue after restoring my 4s to 5.0.1. I've tried to update to 5.1.1 and downgrade to 5.0.1 but each time I get back to 5.0.1 I notice in the phone settings my call waiting is off and I can't switch it on. Once I update with a full restore to 5.1.1, I am able to toggle call waiting off and on. This is definitely related to the downgrade with redsn0w. Can anyone of you guys who tried the downgrade/restore check your phone settings and let me know if you can toggle call waiting off/on. I'm on AT&T.