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
Expect The iOS 5.1.1Untethered Jailbreak For iPhone 4s & iPad 3 With In Days –
A lot of people have been waiting for a while for the Jailbreak for iOS 5.1.1 to come out for iPhone 4s and also the new iPad and we have good news! You can expect the jailbreak tool to be released any time now. The well known french iOS hacker recently tweeted saying you can expect the tool any time now. Not only pod2g is to thank but also “planetbeing” and “pimskeks”.