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
BBC Release Hands On Video With iPhone 4s and Siri –
BBC the first to post a Tech story ? There a first not only a story but they have released a hands on video with the iPhone 4s and the Siri , BBC does not cover the full device but does go over the Camera and also the the Siri personal assistant. The BBC presenter puts Siri through a few tests and it works perfectly.