Those waiting for iOS 4.2's public release may have to sit tight just a little longer: in a surprising move, Apple on Thursday released to the developer community a Golden Master (GM) build of 4.2.1.
The latest build (8C148, up from the previous build's 8C134) is available to developers for all compatible devices--iPad, iPod touch, and iPhone. It seems that in lieu of releasing a second 4.2 GM (or, in the iPad's case, a third), the company has moved forward--though whether Apple intends to publicly release this update as 4.2 or 4.2.1 remains to be seen. Despite the version increase, however, Apple has apparently advised developers not to resubmit their apps, according to a report from MacRumors.
The new GM has reportedly been released to address bugs and errors found in previous builds. Earlier on Thursday, MacRumors published an e-mail sent out by VoIP developer Toktumi--responsible for calling app Line2--that warns customers not to upgrade to the latest version of Apple's iOS. "If you upgrade to iOS 4.2 and you are running Line2 in the background, the ringer will continue to ring even after an incoming call is answered," the e-mail notes, stating that the issue has been designated as "severe" by Apple Developer Support.
It is not known yet whether 4.2.1 was released in response to this specific bug, or to address any of the other issues that have cropped up since the iOS 4.2 GM's first appearance several weeks ago. But either way, it will likely still take some time for the GM to go through all the necessary checks and testing for a final, public release.