I don't know if anyone knows this, but if you hold your iPhone 4 and cover the black strips near the bottom, you lose your signal. 
/end sarcasm./
So I took my bumper off, which I bought for protection, to test my defective iPhone 4. And in the name of all divine fecal matter, my signal went away. Took almost a minute. I was thankful when it got down to one bar, so I could move my hand out of the uncomfortable position I had to hold it in to replicate the problem. Don't know how people hold their phones, but no natural position results in reproducing this. When I hold my phone like I normally do, no problem. So, yeah, it's pretty much a non-issue. But whatever, people will look for any reason to complain, haters any reason to jump on the wagon and grab a tuba, and cheapskates any reason to try to get something for free.
Put my bumper on and went back to life as normal.
/end sarcasm./
So I took my bumper off, which I bought for protection, to test my defective iPhone 4. And in the name of all divine fecal matter, my signal went away. Took almost a minute. I was thankful when it got down to one bar, so I could move my hand out of the uncomfortable position I had to hold it in to replicate the problem. Don't know how people hold their phones, but no natural position results in reproducing this. When I hold my phone like I normally do, no problem. So, yeah, it's pretty much a non-issue. But whatever, people will look for any reason to complain, haters any reason to jump on the wagon and grab a tuba, and cheapskates any reason to try to get something for free.
Put my bumper on and went back to life as normal.