Is it me or the earpiece volume is too low?? I mean I can barely hear the other person on the line. I know that's probably the noise cancellation is kicking in but still that sucks considering I didn't have such a problem with my 3GS which was pretty loud. Defective???
Did you take the plastic screen protector off the front (the one it comes with?) My wife was complaining left an right until I pointed out to her that the plastic film is covering the ear piece. After removing the film she had no problem with the volume level.
I know exactly that small piece because it happened to my friend on his 3gs. So, yes i took it out. With the 3gs I had to put the earpiece volume couple of notches down but with this one its a no go situation. I bet its the noise canceling mic causing this. I wish we can disable it.
When I got the iPhone 4 I just set it up as new and did not restore the backup from my 3GS. I wonder if the volume settings got carried over in the restore and maybe they're "off"? Like ru4real said, try cycling up and down a few times and see if that helps.