I'm trying to see if their is any relation with when the system was bought and people who are having video problems. Selection the option that best applies to you. I'm allowing multiple options. Many of you have had problems with your original unit(s) but had them later replaced with systems that work fine. Input all the units you've had into the poll. If you've had no problems, select all the options that apply to you also. The more data from both sides, the better. It will be interesting to see if this forms a trend. Perhaps this is happening with units made early in the Al iMacs life?