SINCE 3GS and i4 users are reporting the SAME thing it is without a doubt a Software issue with IOS4.
Expect a patch to fix the problem.
Case closed.
Expect a patch to fix the problem.
Case closed.
I'm having the same problem. Phone automatically switched to speaker when I was mid-sentence. Nothing like that ever happened to me with the 3GS. only difference is that my 3GS had a case. I also have the issue w/dropping bars. Still love the device though!
Edit: Only happened that one time and I've taken a few calls since. Maybe a fluke on my part (fingers crossed)?
I have a similar problem, where the proxy sensor will basically lock the screen in the turned off mode during a call and won't let you access the in call menu or anything until you force end the call. really sucks.