Apple said Friday that it was "stunned" to find that the company's iPhones have for years been using a "totally wrong" formula to determine how many bars of signal strength to display.
Apple offered the statement as the reason behind widespread complaints about its latest model, the iPhone 4. Users say the signal strength meter can show a sudden plunge when they hold the phone in a way that covers a small black strip on one edge.
Irate users and tech blogs plastering the Web with comments have jokingly called this the "death grip."
"Their big drop in bars is because their high bars were never real in the first place," Apple said in a statement to users.
There is no industry standard for translating signal strength to bars. Still, Apple said it will fix the formula to one recommended by AT&T, the iPhone's exclusive U.S. carrier. The fix will come through a free software update within a few weeks for the most recent iPhone models, 3G, 3GS and 4.
The iPhone is Apple's top-selling product. The company sold 1.7 million of the latest model in its first three days on sale when it debuted June 24.
Apple apologized to customers "for any anxiety we may have caused. We are also making bars 1, 2 and 3 a bit taller so they will be easier to see," the company said in the statement.
Besides the software fix, Apple is selling a $29 rubber case to minimize antenna-reception problems. But Apple fan sites have found a fix for about $1.
It's taking a pair of scissors to cyclist Lance Armstrong's Livestrong yellow bracelets, or other inexpensive plastic wristbands, cutting out holes for the phones' dock connector, headphone jack and silent-mode toggle switch; and stretching the bands around the phone.
Despite the complaints and lawsuits, the demand for the iPhone 4 at AT&T's stores continues to be strong, a spokeswoman said Friday, adding that stores that have run out will ship phones to customers within seven to 14 days.
"AT&T is thrilled with how sales of iPhone 4 are going so far," Ellen Webner said. "In many of the locations we are waiting for more inventory because the demand continues to be high."
With staff writer Keiko Morris and Bloomberg News