If you search other forums on the net, it seems that every single (well almost...) 24" iMac as that annoying display hum. Although I thoroughly agree that forums tend to attract "problems" (not everyone who gets a flawless machine posts about it...), but it really does seem that everyone has the hum. I'm in the process of sending back iMac #2....in hopes that #3 doesn't have a hum. If you do a search, there is actually quite a lengthy thread about this issue. It also seems that the hum problem is more dominant in the 24" model. All that being said, does anyone have a 24" iMac that does not hum? Moreover, does anyone have a 24" iMac with no noises, hard drive issues, crashes, kernel panics, dead pixels, etc?