Waiting for the white iPhone 4

Apple announced this morning that shipments of the white iPhone 4 will be delayed until "later this year."

Though Apple did not discuss specific reasons for the delay, the company said in a typically concise statement that building the handset "is more challenging to manufacture than we originally expected." It also promised that availability of the black model will not be affected.

This is not the first time that the white model has been delayed. Exactly one month ago today, and just before the iPhone 4's June 24 release date, the company pushed back the white model until the second half of July. Apple CEO Steve Jobs then reaffirmed the July time frame at the company's July 16 press conference.

So, what's going on with the white model? Putting aside the conspiracy theory that Apple is secretly redesigning the antenna, most Apple watchers have speculated that the Chinese supplier charged with processing the iPhone 4 is having trouble painting the glass surfaces of the device. That's certainly possible, but this is not the first time Apple has faced issues with a white handset.

Last year, some white iPhone 3GS owners complained that their phones were overheating, which then caused discoloration on the exterior cover. The problem was not widespread, but the company still updated its heat advisory for all 3GS models. We're not inclined to believe, however, that overheating is relevant here.