Apple releases an open letter to address the iPhone 4's signal issues. However, the company insists that the problems are not due to antenna design. The company blames signal-strength formula that is"totally wrong."

Apple says that the formula causes the phone to display more bars than it should. Also, the company says that sudden drops in signal strength when gripping the phone a certain way is due to the fact that the "high bars were never real in the first place."

Apple insists that the iPhone 4 does not have a defective antenna. The company says that the signal problem is caused by a software problem that incorrectly displays at least four bars of signal strength when it should only display two.

"Gripping almost any mobile phone in certain ways will reduce its reception by 1 or more bars. This is true of iPhone 4, iPhone 3GS, as well as many Droid, Nokia and RIM phones."

In the letter, Apple boasts of the iPhone 4's successful launch and says that the phone has been described by critics as the "best smartphone ever."