I was making some progress on the audio portion of the game and while cleaning up a sound file my PowerBook froze. More lower DIMM slot trouble. I had never looked up to see if this was a common problem, but found a petition for people with the same problem. This doesn’t seem to be just a logic board problem or I wouldn’t need a third replacement. Maybe this machine, or this model, is a lemon. I like Apple products and have never had a problem with either iMac we have, but I’ll continue to be leery of their laptop models.