This update is a hotfix to work around what appears to be a bug in the iPhone browser. This was not reported until after r158 was released and could cause problems for publishing web games for iPhone, which some of our customers have commercial contracts for, so we are releasing a new update with a fix. The problem occurs when opening a game in the iPhone browser in portrait orientation, then switching to landscape, then back to portrait. The game could appear mis-aligned and partially off-screen. It should display correctly in r158.2.
r158 was only released two days ago. If you're updating from r152, there have been many more changes. For more information see the original r158 release notes.