The only minor issue is the light scratches that can be seen on the back of the iPhone. I don't know that it qualifies as an actual problem. As for the phone itself, it's been perfect so far *knock on wood*.
I have the signal issue only at home and nowhere else, free bumper has now totally fixed this issue. Proximity sensor problem was getting very annoying when I first got my phone but since using the bumper it seems to have gone away...go figure so now I'm totally happy with my iPhone
Wirelessly posted (Mozilla/5.0 (iPhone; U; CPU iPhone OS 4_0_1 like Mac OS X; en-us) AppleWebKit/532.9 (KHTML, like Gecko) Version/4.0.5 Mobile/8A306 Safari/6531.22.7)
don't get me wrong I love my iPhone 4 but the proximity sensor thing is getting real annoying... I was talking to my brother and the call went on speaker 3 times In a row... I was home I can't imagine this happening to me on public...