iPhone 4s call pickup audio delay?

[kargold]

I got fed up with that problem and went to the Apple store with my iPhone. The "Genius" who assisted me scanned the software and all was fine. Then he called my phone and there was no delay, but he reasoned that since they have a network repeater in their store for cellular service, that it was most likely a hardware issue. He swapped my phone for a new one and told me to call him when I got out to my car. I did; he called me back and my new iPhone answered perfectly. So.... It's the phone. Exchange it while you can if you already have and you still have the problem, try again. It's the phone.

 

[sony83]

So did exchanging for a new one solve the issue?

 

[zBoost]

I've had this on my 4s and my 5 now. Im thinking about if I shouldn't change my SIM as it is an old one...