San Francisco:
On Monday, Consumer Reports, America's trusted source of product reviews, said it would not recommend the iPhone 4 because of a hardware flaw with its antenna that sometimes resulted in dropped calls. The independent consumer magazine also cast doubt on Apple's recent explanation that a software bug had caused the widely reported problem. Apple did not return requests for comment.
Consumer Reports did not slap the iPhone 4 with a "don't buy" warning, which it sometimes issues for shoddy or unsafe products. But it said that because of the design flaw, it would not recommend it as it did with the previous version of the iPhone, the 3GS.
The next question is, Will any of Apple's customers even care?
The various versions of the iPhone have been panned a number of times for myriad problems, real or perceived: slow network, cracked screens, dropped calls and no support for a popular Web video format. But iPhone sales have surpassed even the most optimistic forecasts and helped make Apple the most valuable company in the technology industry.
And despite early reports of problems with the iPhone 4 antenna, Apple sold 1.7 million units in just three days, making it the best-selling new technology gadget in Apple's history.
"It's iconic, it's cool, it's the 'it' device and people want it," said A. M. Sacconaghi Jr., an analyst with Sanford C. Bernstein & Company.
Still Mr. Sacconaghi and other analysts said Apple could eventually suffer from the bad publicity it had received over the antenna problems and for its seemingly contradictory responses.
Apple has promoted the iPhone 4's innovative design, including its antenna, which is built into a steel band that encases the phone.
After users reported problems with signal strength and dropped calls when they touched the lower-left portion of the phone, however, Apple suggested that consumers hold the phone differently or use one of many bumpers to insulate the antenna. It also said that all phones suffered from similar problems when they were cradled a certain way.
These comments were widely laughed at in gadget blogs.
A week later, Apple said it had found that because of a longstanding software bug, the iPhone 4, and its predecessors, often overstated signal strength. The company promised a fix soon.
In a blog post on Monday, Consumer Reports challenged those explanations.
Michael Gikas, a senior editor for electronics, said engineers performed a series of tests on three iPhone 4 handsets in a lab. They found that when a person touched the lower left portion of the antenna, signal strength "can significantly degrade enough to cause you to lose your connection altogether if you're in an area with a weak signal," Mr. Gikas wrote.
Consumer Reports also said that it had tested other smartphones that ran on AT&T's network, including the Palm Pre and the iPhone 3GS, and that none had the same problem.
Mr. Gikas also wrote, "Our findings call into question the recent claim by Apple that the iPhone 4's signal-strength issues were largely an optical illusion caused by faulty software."
The review from Consumer Reports, which has eight million paying subscribers, comes 10 days after the magazine played down the problems with the iPhone 4 antenna. But in an interview, Mr. Gikas said the earlier report had been based on first impressions, not thorough testing.
Mr. Gikas said the problem with signal strength could be fixed by insulating the antenna with a bumper or even a piece of duct tape. And he said that the phone, as many happy users have reported, is better than earlier iPhones on multiple levels.
"The iPhone 3GS was always recommended. The iPhone 4 isn't, even though it scores higher on a number of areas," he said. "We think either Apple should supply free cases for the phone or come up with another solution. That's why we are not recommending the iPhone 4."
In comments posted on sites across the Web, dozens of iPhone 4 users dismissed the findings as unimportant.
But other consumers said the problems with the iPhone 4 and Apple's response gave them pause.
"I'll buy it the day Apple fixes it," said Bruce Namerow, the owner of a Web consulting company based in Washington. "I don't see how they can sell a phone that you can't hold any which way you want. That to me is unbelievable."