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
Gorilla Glass 2 Becomes Thinner But Stronger –
We have seen more and more Apple devices released which take advantage of Gorilla Glass which is said to be strengthened and make the whole device a lot tougher. We have seen a demonstration of the new Gorilla Glass at CES 2012 which shows it to be at least 20% thinner and keep the same strength. The new Gorilla glass is said to bring a better image and improved touch response in handsets. It has been debated whether Apple are still using Gorrilla Glass in the iPhone’s today.
We have more CES 2012 coverage which you can find HERE . Which will be updated through out the week.