Has anyone noticed that with a keyboard skin, the sound is much worse (muted, no treble) on the MBA? Is this common to all Macs or is it only on the MBA? Is the keyboard the, y'know, vent or something for the speakers? I have a 13" MBA, and a Moshi clearguard skin.. I'm a first time Mac switcher so I didn't know if this was common. I do 900miles of research before every purchase, even been lurking around this forum for ages now, but I never read about anything like this - only that keyboard skins may or may not make it run warmer. PS. I'm not complaining, I still love my MBA to death..