iPhone 4 locking up during a call

Hmmmm... have you tried resetting the network settings in Preferences? Or restarting the iPhone? Or possibly restoring your iPhone in itunes (of course, after backing it up). I wonder if any one of these will fix your problem.

Exact same problem here. The screen goes black after a call so that I can't end the call. Then when the screen does appear after several seconds by touching the home button, the slide will not work. My phone also switches automatically to facetime during a call sometimes, while the phone is to my ear and without me making the selection. Any help out there?

Same issue here. I was on speakerphone last night and couldn't minimize the phone application so I could enter Safari. Only way out was to end the call.

I've had the same problem. After EVERY call, the screen goes black. I have to fiddle with the top button and the home button in order to get the phone back to where I can use it.

Hey APPLE! Wake up and have the courtesy to to reply to this thread.

Same issue here. Seems like quite the large software bug. Shouldn't crap like this have been sniffed out in beta testing phase.

The worst part is no reply from Apple at all. Get on it kids. Ignoring it won't make it better.

Try restoring as a new phone... When you restore from a 3GS backup all sorts of 3GS settings get introduced...

Same problem here. However, I did today discover that my using a Belkin case designed for the 3G models meant the proximity sensor was covered up. This, I believe, caused the screen to stay black. I've experimented with the phone since removing it from the case and it's been OK. So far...

Message was edited by: matamanoa

I have had my iPhone 4 for about 4 weeks and only started having the lock up problem recently. Just as described in most of this thread, my screen will sometimes go black during a call (timer setting doesn't seem to matter) and then when I get screen back (only way seems to be lock button on top), then I pushing the End button doesn't do anything but cause the screen to go black again. This has got to be a software issue.

I have the problem with and without the case (free Griffin). Mine also locks to the point that I can't end the call and have to do a hard restart.

I just received my iphone 4 yesterday. I had the same problem. I upgrade the os to 4.02 and still the same problem. I read some of the posts and decided to test the theory about the proximity sensor. I have a griffin case on my phone. When the phone is in the case, the proximity sensor doesn't function correctly and it locks up. When its out of the case it works just like it should. I called myself on my office phone and moved the phone back and forth from my face. Once the screen blanks when the phone is in the case, the only way to get it to unlock is to pull it out of the case. But if I use the phone without the case, I have no problem at all it works flawlessly. It blanks when I put it near my face and immediately unlocks when I take it away. I hope the free case from apple will solve this problem because I am paranoid that I will drop my phone without the case and destroy it.

Am having the same problem. It happens about 2/3 of the time. Also, can't get to an incoming call because the screen is black and locked up/frozen.

I've had my phone lockup when trying to end a call but also when pressing the sleep/wake button. Really frustrating when trying to make a call and it's locked up and you must wait through a phone reset as the only way to bring it back.

Same here, took it out of a Case Mate cover, and now it works fine...the case was for 3G, I understand t...

I am having the same issues. Hopefully this will be addressed by Apple sooner, rather than later