What's wrong with iPhone 4's antenna?

The rumors are true: iPhone 4 signal strength wavers when the device is held in the hand. Isn't that like the typical position for holding a cell phone? I can confirm the behavior with the unit FedEx delivered about 3 hours ago. When the phone is flat down, I see four to five bars. When I hold the device in my left hand, the bars slowly go down until either there is one bar or "searching" appears on the screen.

I want to thank Justin Horn for bringing the problem to my attention. I had complained about "searching" behavior on Twitter. He posted: "Is the new iPhone 4 antenna design causing signal issues?" Gizmodo has crowdsourced the story, getting readers to confirm the declining bars scenario; good for Giz practicing some fine "process journalism."

By appearances, the act of holding the phone impares signal strength. I'm not so bothered because I typically use a Bluetooth headset rather than hold a phone. Flat or holstered in a case are the handset's typical positions when used. But many other people do palm their iPhones when making calls. More significantly, the problem raises possibilities of a flaw in the newly redesigned antenna array. In my brief testing on one phone call, the recipient reported degradation in calling quality -- "crackling" -- after the bars receded to none.

A cell phone should be a phone first and everything else second. It's unclear yet how serious the problem really is and how much it could affect calling quality on AT&T's "seemingly always dropping calls" network. The problem also raises questions about a known design flaw. I ask because of Apple's iPhone "Bumper" guards, which from their announcement seemed strange starter accessories to me. But what if using the Bumpers separate the metal band from the hand enough to remove any signal interference? I don't have the Bumper accessory, so I can't say. Anyone with iPhone 4 and Bumper want to chime in with an answer -- in comments?

[Update: If I hold the phone out from my palm, but sill firmly gripped, the number of bars diminishes only slightly. The signal strength decline is most bothersome when left thumb covers the volume keys and silent button and remaining side of the phone presses against the palm.]

Otherwise, my initial reaction to iPhone 4 is favorable. The design and "Retina Display" are hugely appealing. The phone feels surprisingly solid in the hand, and it is responsive, as in fast.

FedEx delivered iPhone 4 in the early afternoon Pacific Time. The deliveryman said he had about 40 phones on the truck when he started the daily run. I was near the last of his iPhone 4 deliveries.

Phones are looking to be in short supply for tomorrow's official launch. A friend went into a regular Apple Store -- in an East Coast mall -- to make sure there was a handset reserved from him. He got a "Yes" and a warning: Only 1,000 phones in stock, and they'll be available on a first-come basis. An Apple Store employee suggested lining up outside the store before 5 a.m. for the 7 a.m. opening.

Regarding iPhone availability, I've got to wonder about the white iPhone 4 delay. How much did white models factor into Apple's logistical planning and when in the manufacturing process did problems occur? The answers might explain why there are already supply shortages, beyond demand, if Apple planned on white but pulled the models late in manufacturing and distribution process.