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
Apple Seed New 10.7.3 beta To Developers –
Apple released the last version of Lion , 10.7.2 was released to the public in October. This is not the first version of 10.7.3 we have seen seeded to developers and we are not seeing much different. The only thing different so far is that Apple are asking developers to focus on different areas. The last build developers were asked to concentrate on the iCloud side of things in the OS but no Apple are asking them to focus on spotlight and safari .