I recently received a 1gig memory upgrade that I ordered online. My problem was the single screw that needs to open in order to install the memory would not turn. I didn't want to strip the screw, so I made an appointment with one of the Apple geniuses. I took in my new 20" iMac this past Saturday and the "genius" was also unable to turn the screw. It was probably manufactured wrong. Without me even asking, the "genius" went in the back room and brought out a new IMac for me. This is an example of good customer service. I've become so use to bad service from corporate America. Thank you Apple for doing the right thing!!