I've just got off the phone with an AppleCare tech after our replacement 27" 3.4GHz iMac started having issues - on the day it arrived! They are going to replace the machine again, but while I was on the phone I asked whether this had been a recurring issue, and was told that they were aware of an issue. He said that while there wasn't a full recall on the BTO iMacs, the engineers were trying to 'capture' as many as possible to find a solution - the thinking was that it was more likely to be a software issue than a hardware one. Apple customer service is always exemplary, but that doesn't stop it being a bit of a pain in the arse to have to keep boxing these computers up and sending them back. I would have thought that these issues should have been caught before the release. Just thought I'd pass this on... I guess if you're in the market for a BTO iMac, and don't need it right now, it might pay to hold of just a little bit longer!