By AppleInsider Staff

Published: 07:00 PM EST (04:00 PM PST)

Apple on Tuesday evening released to its iPhone developer community the second private beta of iOS 4.1, a much anticipated update to the company's mobile operating system aimed at remedying a number of outstanding issues with the new iPhone 4.

The software, labeled iOS 4.1 beta 2 build 8B509b, was made available in five distinct distributions, one each for the iPhone 4, iPhone 3GS, iPhone 3G, iPod touch 3rd generation and iPod touch 2nd generation.

Most critically, the release is expected to include a fix for proximity sensor malfunctions on the iPhone 4. From the onset, users have found that the touchscreen on their iPhone 4 will sometimes activate while on a call, resulting in accidentally pressed buttons that can place a call on hold or even end it and dial a different number almost instantaneously.

During a press conference two weeks ago, Apple chief executive Steve Jobs said the company is aware of problems with the proximity sensor on the iPhone 4 and added that his team was working on a software fix that is expected to be included in the next iOS update -- presumably iOS 4.1.

The first beta of iOS 4.1, released to developers a couple of weeks ago, included a new version of the iPhone's modem firmware (02.07.01), the ability to add FaceTime numbers as phone favorites, a remodeled version of GameCenter, and cosmetic changes to the camera app that reposition the flash and camera swap buttons when handset it shifted to landscape mode.

Released in June, iOS 4.0 is already said to be powering half of all the iPhones currently in use by consumers worldwide.