Iphone 4 won't hang up

Listen up everyone! Problem solved after I downloaded the latest software update — 5.1 (9B176)

Thanks for all the input.

i tried to on my 3G service when my 5.0.1 is hang . and everything solve.

i tried your advice but not working. phone still cannot call or receive call or sms. also tried by on and off 3G also not helping...tried to update os also failed...

is there any other way??

I have been having the same problem as a lot of you where I could not end a call. Today I was on a call and right before I ended my call I received an email. I have push turned on.

I could not hang up without hitting the button about 10 times.

I talked to my cousin who also had an iphone and we compared settings. She has both "push" and "fetch" turned OFF for her email.

I turned mine off and cannot get it to fail now! While it should work with it on it doesn't. The whole phone seems faster now.

If you have the "end call" problem try turning off "push" and set "fetch" to manual and let us know if that fixed the problem. If it does at least we know the problem and can report it to apple.

Thanks.

Where is apple's response to all of the above issues????