Edit: After half day, my wife’s Mac started having the same problem. I have then applied the solution that I found in the Apple
Best Advice : Walt Mossberg Warns Readers Not To Buy A Mac Just Yet –
Walt Mossberg speaks out
Apple is overdue for redesigned laptops, especially in its MacBook Pro line, and it is a good bet that new, possibly heavily redesigned, models will begin appearing later this year. Current Macs will likely be upgradable to Mountain Lion, but if you buy now, you’ll miss out on the likely new hardware.