Ars Technica summarize a problem with an App Store server that generated faulty DRM code for several days, causing downloaded Mac and iOS apps to crash on launch and users to hit developers with angry 1-star reviews. Apple has fixed the problem, which affected at least 120 apps and tens of thousands of users who downloaded updates or new apps during the time the problem occurred. Apple also reset the version numbers of affected apps to conceal (but not remove) the angry 1-star reviews. If you downloaded any apps around 5 July 2012, it’s worth checking for updates again. follow link
Sleep (and Lock) Your Screen
When you are walking away from your computer, it's fairly common practice to start your screen saver and lock your screen. But did you know that there is a built-in keyboard shortcut in Mac OS X to sleep the screen?
Press Control-Shift-Eject and your monitor sleeps without engaging the screen saver.
Apple Fixes Crash-Causing App Store DRM Error