According to the Wall Street Journal, while the magazine found other aspects of the phone laudable, it disagreed that the well-publicized signal reception problem was easily fixed by a software patch as the computer giant contended.
"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 testers wrote in a post on the Consumer Reports website.
They noted that the older iPhone 3Gs and other brands of smartphones, such as the Palm Pre, did not show the same signal degradation problems that the iPhone 4 has displayed.
Apple's new design places the antenna on the outside of the phone in a silver band that encases the body. Almost immediately after its release, many consumers reported that placing their hands on certain parts of the phone increased the likelihood of their calls being dropped.
Apple attempted to address the issue by releasing an open letter on July 2, in which it said that an internal investigation revealed that a software glitch led the phone to misrepresent signal strength. The company said it would issue a software update to fix the problem.
Despite the signal issue, sales of the phone have been brisk. Over a million units were estimated to have been sold on the first day the iPhone 4 was available and wait times currently run to about three weeks for the device.