During call, face is hitting Mute, End, Contacts, etc. buttons.

Happening to me as well. I can't lock the call either as Apple disabled the ability to lock the iPhone (except when using the speakerphone/headset) in this version. It's really annoying!!!

I've read that this is only an issue when you restore the iPhone4 from a 3G(s) backup. If you set up your new iPhone as new, it apparently fixes the issue. Kind of an unattractive fix, but for those who cannot wait for the 4.1 release, perhaps it's worth a shot.

The same thing has been happening to me and all of a sudden I hang up on the person. I restored from an ipod touch backup.

Yep, I have this same problem. Just adding to the list so Apple can see order of magnitude.

I'm having this issue as well. Extremely annoying, especially while talking in the dark when the screen comes on, then goes black, then comes on, then goes black. Please fix this Apple. Please.

I restored from a backed up 2G iPhone.

This has been my ONLY issue with the phone thus far. 🙂

Same happening here to my wife's iPhone 4, although I am not having an issue on my 3GS with OS4.0.

So annoying being cut off all the time.

Dan

I'm having the same issues. Currently working with Apple Support to resolve. He asked me to perform a restore on the iPhone and to select "Setup as New iPhone" in iTunes. The restore had no effect on the problem.

Apple support assured me that most iPhones are not experiencing this issue. Could it be faulty components within certain production lots?

I have the same problem... Need a fix

I've had this problem since I got the 3Gs in January (and I still have the 3Gs). I never knew the screen was supposed to turn black until my friend got the iPhone 4 and said that the screen is staying on and she's face dialing. She said this didn't happen when she had the 3Gs, which was a surprise to me since I thought this was a feature Apple forgot to add to the iPhone 3Gs. I said maybe there's a setting that can fix this- but when I checked there was nothing... it's kind of frustrating reading this discussion and seeing reply after reply "I have this problem too... me too, yea me too!" Can we have a solution to this problem already please Apple?

UGH. This is SOOOOO annoying. I have had the iPhone 3g for near two years and thought it would be a nice upgrade to go to the iPhone 4. This is BY FAR the most annoying issue with this phone. Everytime I try to talk holding the phone with my shoulder while multitasking, I dial in the other person's ear, turn on music from the ringtone, disconnect or something else.

APPLE: PLEASE, PLEASE take this seriously and fix this. We are all VERY brand loyal and want to remain so, I'm sure, but this just is too annoying for a 300$ phone (with contract).

Please and thank you! 🙂

So I just read something from another forum which resolved this for me on my 3Gs iPhone. I realized since I have a decorative skin on my phone it was covering the small hole which is the sensor for when your iPhone is held close to your ear. I removed the skin over the hole and NOW IT WORKS! Here's what I found for 3G/3Gs and 4:

If you hold the two phones (3G/3GS and 4) you will notice that the 3G/3GS had 3 little dots to the left hand side of the earpiece, these are what recognized the change in light for your ear during a phone call, auto brightness etc.

If you now look at the iPhone 4, they have moved this to one small bar above the earpiece (as the front facing camera now covers where they used to be).

Solution? Hold the phone a bit lower lol!

This may also help those with their iPhone 4 issue too!

I guess the best thing for me to do would be to call Apple and see what they say about it. Cuz I just got this phone yesterday and have had all my calls ended before of my face ending the call and making new calls! Super annoying! I hope Apple fixes this soon. I have had the first gen iphone since Feb 2008 and NEVER had this problem!

I did my restore, and the problem did not go away..

I've had every iPhone, use 3600 min a month, and the new #4 is a pain to use. My face turns speakerphone on and off, dials calls while I'm talking, and turns mute on and off.