Long-time lurker here who's gained a lot of great knowledge from this board. Wondering if anyone might be able to help me out. We (like a lot of people) were waiting for the new iMacs to come out, and opted for a 3.4GHz i7 on release day. Long story short, that one ended up getting returned because it would continually be unresponsive. I lucked out everywhere else though - silent HDD, no yellow tint/dead pixels etc. So the replacement arrived yesterday, and I spent a few hours getting it all set back up again. Noticed that there was a considerably noisier HDD in there and a dead pixel on the screen, but am quite happy to live with that. But, at about 3AM we were woken up by a REALLY loud noise that I was convinced was the fire alarm. Turned out it was the iMac making a series of beeps - all I could do was kill the power and get back to sleep. When I got up this AM, I expected not to be able to boot up due to bad memory or something similar - but it booted just fine, passed Apple's hardware test and got through the GeekBench test with the same scores as before. Could anyone shed any light on this please?