Can anyone help? I just bought a Daewoo DP42SP 42" plasma screen and I get an annoying high frequency sound from the back of all the time (Like the noise a fridge makes but quieter). Whenever the screen displays pictures that are light in colour the sound gets more audible but then when the screen is black the sound virtually disappears. Is this something I have to put up with, is there a quick fix or do you think that this could be a warranty call out? All help much appreciated.. Thanks Nick.