According to Bloomberg, one of Apple's senior engineers raised concerns a year ago over the potential for the iPhone 4's design to cause dropped calls.
We've received only one report, so take it with a hill of salt: A Gizmodo reader claims that, after Apple replaced his iPhone 4, he couldn't reproduce the sharp loss of signal. He says that the hardware seems slightly different:
The first iPhone 4 class action suit against Apple and AT&T has been filed today in the United States District Court for the District of Maryland. The lawsuit focus on the antenna design problems, making several claims: Updated
Richard Gaywood—Ph.D in wireless network planning from Cardiff University—has tested the iPhone 4 communications problem. Before, he thought there were no problems. Now, his conclusion is clear: "The iPhone 4 is a fantastic device but a lousy phone."