Apple has started pushing out iOS 4.0.1 for iPhone users. The primary feature in the software update is a chance in the way iOS determines how many bars of signal strength to display on the iPhone 3G, 3GS, and iPhone 4.
Unless you’ve been hiding under a rock, you’ve probably heard that many iPhone 4 users have experienced signal loss and dropped calls when they hold the phone in their left hand with their palm covering the lower left corner. The software update doesn’t actually fix this. Instead, Apple suggests that while there is a signal loss when you hold the phone (or any phone) in some ways, the real problem is that Apple has been incorrectly identifying signal strength for the past few years.
In other words, you might only have 3 bars when the phone says you should have five. And when you squeeze the phone, you don’t drop from five bars to two… you drop from three to none, which explains any dropped calls you might experience. So umm… yeah, this fixes the signal reporting issue. It doesn’t seem to fix the bit about dropping calls though.