Apple said Friday it was "stunned" that its iPhone 4 used erroneous formulas to calculate signal strength, and promised to issue a free software patch to resolve the issue that has already triggered lawsuits.

In a letter directed to users of the latest iPhone model, the company said the signal drop was likely exaggerated because its formula was "completely wrong," displaying four or five bars in areas with a very weak signal.

It also reminded user they could return their smartphones within 30 days of purchase for a full refund.

Apple shot down users and outside engineers who said the signal problems were due to faults in its new antenna system, which is incorporated in the casing.

Some complained that cupping the smartphones, which launched a week ago with blockbuster sales, in a way that covers the lower left corner strangles telecom service signal strength.

But Apple said users' "big drop in bars is because their high bars were never real in the first place."

The company said the incorrect formula was present in the original iPhone -- released in 2007 -- and promised to fix it by conforming to AT&T guidelines for signal strength display through a free software patch that would be issued within a few weeks.

The software update will also be available for the iPhone 3GS and iPhone 3G.

As part of its antenna system to improve signal strength, the iPhone 4 has silver edging.

"Gripping almost any mobile phone in certain ways will reduce its reception by one or more bars," Apple said.

It noted that some iPhone 4 users had reported a drop of four or five bars when tightly held in a way that covers a black strip in a corner of the silver edging designed as part of the antenna system to improve signal strength.

"This is a far bigger drop than normal, and as a result some have accused the iPhone 4 of having a faulty antenna design," Apple added.

"Upon investigation, we were stunned to find that the formula we use to calculate how many bars of signal strength to display is totally wrong."

In many instances, Apple's formula mistakenly displays two more bars than it should for any given signal strength, the company said.

The update also make the first three bars slightly taller so they would be easier to see.

Apple maintained the iPhone 4's wireless performance remains "the best we have ever shipped."

earlier related report
IBM endorses Firefox as in-house Web browser
San Francisco, Usa (AFP) July 1, 2010 - Technology giant IBM wants its workers around the world to use free, open-source Mozilla Firefox as their window into the Internet.

"Any employee who is not now using Firefox will be strongly encouraged to use it as their default browser," IBM executive Bob Sutor said Thursday in a blog post at his sutor.com website.

"While other browsers have come and gone, Firefox is now the gold standard for what an open, secure, and standards-compliant browser should be."

Making Firefox the default browser means that workers' computers will automatically use that software to access the Internet unless commanded to do differently.

All new computers for IBM employees will have Firefox installed and the global company "will continue to strongly encourage our vendors who have browser-based software to fully support Firefox," according to Sutor.

New York State-based IBM, known by the nickname "Big Blue," has a corporate history dating back a century and now reportedly has nearly 400,000 workers.

"Today we already have thousands of employees using it on Linux, Mac, and Windows laptops and desktops, but we're going to be adding thousands more users to the rolls," Sutor said.

Sutor is the vice president of open source and Linux at IBM, which launched an Open Source Initiative in 1998. Open-source software is essentially treated as public property, with improvements made by any shared with all.

Firefox is the second most popular Web browser in an increasingly competitive market dominated by Internet Explorer software by Microsoft.

Google Chrome has been steadily gaining market share, last week replacing Apple Safari as the third most popular Web browser in the United States.

"We'll continue to see this or that browser be faster or introduce new features, but then another will come along and be better still, including Firefox," Sutor said.

"I think it was Firefox and its growth that reinvigorated the browser market as well as the web. That is, Firefox forced competitors to respond."