The below problem is ONLY specific to the first G5 iMacs delivered in Australia ONLY. Apple are aware that the stated iMac G5's above have noise issues with the first revision of power supplies. The problem has been fixed in the current models. If you have a noisy power supply (buzzing noise coming from below the apple logo) then you may have a faulty power supply as confirmed to me by Apple Australia. The buzzing noise should be noticeable in a quiet environment. If you have a buzzing noise ring Apple and press 9, talk to the operator and ask to be put directly though to a guy called 'Mel'. Tell him about the problem, and he can help you fix the issue. Anyone have the same problem?