I've been reading through the threads regarding the iMac's screen flickering and discoloration problems. One thing I'm not clear on though is why people keep brining up week 4 and 5 machines so often in the forum. Is the problem more pronounced in machines manufactured during those weeks? I see more people complaining about those models than any others. I ask because I'm considering buying an iMac for my wife, but want to know the likelihood of getting a bad one. I'm in no hurry of course, I'm going to wait at least two weeks to see if this next batch has better luck.